534 



THE GARDENERS' CHRONICLE. 



water sponges, were less frequent, but occurred in 

 manv. In a few cases, where the acid caused effer- 

 ve ence, there was calcareous matter present, but in 

 roost, this was not the case. Of course, in those cases 

 in which the proportion of earth was small, the residue 

 consisted chiefly of the insoluble organic matter, through 

 -which, however, Diatoms and Phytolitharia were 

 scattered, in greater or smaller proportion. In the 

 cases where the proportion of earth was larger, the 

 residue was much richer in Diatoms and Phytolitharia, 

 but almost always contained also the dark insoluble 

 organic matter. In several, the proportion of Diatoms 

 in^the residue was so large, that it had the appearance 

 of a regulir Diatomaceous gathering, after boiling with 

 acids. The most remarkable soils in this respect were 

 one from the Sandwich Islands, one from Lebanon, one 

 from the roots of a German Moss, and one from Ailsa 

 Craig. It is to be noticed, however, that Diatomacese 

 were fouud in every case, without exception, and that 

 in all their proportion to the whole non- calcareous 

 earthy residue was considerable, and often large. In 

 manv* of those where the proportion of earth was 

 smallest, there was no siliceous matter in the residue, 

 except D-atomacese and Phytolitharia, The ^ soils 

 examined were from various and distant localities ; 

 there were about 20 from the Andes, several from 

 Brazil and other parts of South America, a few from 

 North America, a few from the West Indies, one from 

 the Sandwich Islands, one from New Zealand, a few 

 from India, one from Lebanon, a good many from 

 Germany, some from France, a few from Spain, and 

 some from Britain. The great majority of the species 

 of Diatoms in all these were found to coincide with 

 our British forms, but a good many species occurred in 

 the exotic so 1«, which have not yet been found in Britain, 

 and most of these not even in Europe, but which have 

 been figured by Bailey, Ehrenberg, Kutz : ng, Raben- 

 horst, &c. A good many were observed, which, so far 

 as I know at present, have not yet been figured or de- 

 scribed. Lastly, a certain number of species, lately 

 fouud by Smith, Greville, and others, as well as 

 by myself in Britain, and some of which are 

 scarce, have occurred in these exotic soils. 3. On 

 the Effects of the Severe Frost of last winter on Plants 

 in the neighbourhood of Sligo, by the Right Hon. 

 John Wynne, of Haslewood. The following facts indi- 

 cate the severity of the frost : — First. The adjoining 

 lake was frozen across, so as to bear skating for about 

 one-third of its length for about a fortnight— a circum- 

 stance which never occurred in my recollection, and I 

 believe only once during the lifetime of my father, who 

 lived to be 85, and spoke of his having once skated 

 across the lake, which we did several times this last 

 season. Secondly. The number of birds killed by it 

 was very great, especially sea birds — curlews and sea- 

 gulls. After the thaw the sea-shore was covered with 

 dead sea fowl. The thermometer at Markree Obser- 

 vatory, only six miles from this, and equally near the 

 sea, on the 12th of February stood at 13.2 Fahrenheit, 

 and on the 13th 17.6 ; on the 17th, 17.2 ; on the 18th, 

 15. There was no snow here during the continuance 

 of the frost— only about 2 inches fell on the first day of 

 the thaw, so that the plants were exposed to its full 

 severity. Some days after its commencement I had 

 the roots of the plants marked * covered with saw- 

 dust, but by no means soon enough. Plants killed — 

 Erica arborea, Erica ciliaris, growing in bog; same very 

 slightly injured in garden ; Phyllodoce cserulea, Rho- 

 dodendron altaclerense, Adiantum capillus Veneris, from 

 Arran ; *Davallia canadensis. This Fern has been 

 for years in the rockery, covered during frost with a 

 piece of calico. Plants much injured : Edwardsia 

 tetraptera, old plants on west wall ; E. microphylia, old 

 plants on north wall ; Laurus nobilis, *Myrtus com- 

 munis, on wall, both narrow and broad-leaved ; Ulex 

 europseus in some places, not the least in others; Calluna 

 vulgaris, in bog ; *Abutilon striatum on east wall, out 

 four or five years ; Daboecia polifolia, Verbena triphy Ha, 

 "*Aspidium longifolium, covered with calico. Slightly 

 injured as to the leaves : Arbutus Unedo, much injured 

 a few miles off ; Photinia serrulata, both on wall and 

 standard very slightly ; Viburnum Tinus, some plants 

 close to others which were much injured received no 

 injury • *Ceanothus azureus on south wall. Uninjured : 

 Fuchsia globosa major, on east wall ; Magnolia grandi- 

 flora, on south wall ; M. tripetala, standard ; Rhodo- 

 dendron arboreum, Rhodothamnus Chamseeistus, Arbu- 

 tus Andrachne, Olea excelsa, standard, sheltered ; 

 Daphne pontica, Pseonia Moutan, Pawlovnia imperialis, 

 Erica mediterranea, also Irish variety ; Cedrus Deodara, 

 Araucaria imbricata, Cupressus tomentosa (*ic),Taxodium 

 sempervirens, Pinus canadensis, Abies Webbiana, A. 

 cephalonica, Cryptomeria japonica, Quercus cocci fera, 

 Juniperus bermudiana, Buddlea globosa, Cistus ladani- 

 ferus, Garrya elliptica, Woodwardia radicans, covered 

 with calico, as it has been for some years ; Tricho- 

 mane* brevisetum, Pinguieula grandiflora, Anomotheca 



CrUenta. Mimulna mrvcViarM* 



Stockwood Golden Hamburgh Grape, a sort first 

 exhibited at the Horticultural Society's last July 

 meeting, when it gained a Medal, as a valuable novelty. 

 This opinion was now confirmed, it being regarded 

 as a valuable acquisition to White Grapes, of which 

 with the exception of Muscats, it was pronounced to be 

 the best ; also fruits of the Stan wick j and Elruge Nec- 

 tarines from Arundel Castie, both excellent of their 

 kinds ; and a good looking juicy sub-acid Cherry from 

 Mr. Rivers considered to be valuable for its lateness. 



L Augij ^ n, u i 



tainiug in its 

 granules. 



cavity a thick 



dotted mm 

 is examined 



nk 



If one of these plants 

 by the microscope while floating 

 will be seen to group themselves toeether'un'L 8 ^ 

 uutil very soon a number of cell-like hM; Jl ™* 



t ^OMOLOGicAt, August 6.— Anniversary. Mr. Rivers 

 in the chair. A report on the state of the Society's 

 finances was read, from which it appeared that after all 

 expenses were paid there remained 27/., together with 

 some outetandmg debts due to the Society, in the hands of 

 the treasurer Ofhcers for the ensuing year were then 

 nominated, when Sir Joseph Paxton, M.P., was elected 

 President ; Mr. Davidson, Acting Secretary, at a small 

 salary; and Mr Taylor (of Me*rs. Webber's), 

 Treasurer, v 1C e Mr. Spencer, retired. Amongst the 

 more important fruits examined on this occasion were 



escape into the 



esicles lik»2 



$Lotitt$ of &00U. 



The Philosophy of Reproduction. By R. J. Mann, M.D. 



Small 12mo. Longmans, pp. 160. 

 It is long since we met with a work in which the 

 mysteries^ of nature have been more happily and 

 intelligibly revealed. Dr. Mann's style of conveying the 

 facts of high science in familar language is a model not 

 only of skilful generalisation, but of pure English, 

 undefined by fearful Greek and Latin stains. That 

 reader must be very dull of apprehension who fails to 

 follow his lucid narrative even into the deepest depths of 

 scientific revelation. We only regret that he never 

 gives an authority for his statements, which necessarily 

 rest mainly upon the researches of others, and which we 

 certainly cannot in every case affirm to be susceptible 



of proof. 



Without, then, professing to endorse all* which this 



most instructive and entertaining volume relates, we are 

 justified in saying that it is a lucid explanation of the 

 opinions at present entertained by philosophers con- 

 cerning what were once thought to be the impenetrable 

 secrets of reproduction among living things, whether by 

 eggs, seed, or other contrivances. From the animalcules 

 that only microscopical eyes have ever looked upon, up to 

 man, the most perfect of created beings, the chain of 

 analogies is completed, as it also is between the green 

 scum that floats upon our inland waters and the Pine 

 of a thousand years that covers them with its shadow. 

 In all these widely different forms the exact analogy of 

 reproductive phenomena is sketched (for we have only 

 a sketch) with very remarkable skill. 



In explaining these curious operations, Dr. Mann 

 takes as his point of departure Carpenter's happy idea 

 of dividing all living matter into two forms, the Zoon 



and the Zoom : — 



" Each entire generation is in his nomenclature a 



zoon (zoon j Greek for animal) ; and every separate 



vesicle that forms an individual in this zoon is a zooid. 



Thus, suppose, for instance, that one active vesicle of 



the yeast plant were dropped alone into a tun o* sweet 



wort ready for fermentation, and were there to bud and 



multiply until a hundred millions of similar vesicles had 



been produced, each of these hundred millions would 



be one of Dr. Carpenter's zooids ; but all the vesicles 



contained at any one time in the tun would be a zoon. 



This is a very important generalisation, on account of 



the facility it affords for explaining what happens when 



complex instead of simple structures of organisation are 



concerned. 



" Where the lowest and rudest kinds of vesicular 

 life are alone in question, each new generation is cast 

 off as rapidly as it is produced, and thus the entire 

 zoon is widely scattered over the face of the earth. 

 This, however, only happens with such rudimentary 

 structures as the monad animalcules and many of the 

 diatoms. In all other instances, the zooid vesicles that 

 are formed from one parent show more or less of a 

 tendency to cling together. It has been stated that the 

 vesicles of the yeast plant hang together in strings so 

 long as the fermentation of the liquid in which they are 

 developed continues. Many diatoms form chains after 

 a similar fashion, sometimes holding together by the 

 corners of their quadrangular frustules, at other times 

 constituting staircases and jointed bars of very singular 

 outline. In the higher developments of animal life, all 

 the zooid generation produced from a parent vesicle is 

 retained in one skin. None are allowed to be scattered 

 abroad until their work in the individual economy is 

 finished. Each animal is therefore in itself one zo m of 

 Dr. Carpenter. In the highly developed plants, the 

 zooids of a single generation are also attached together; 

 but in this case subordinate clusters are capable of being 

 removed from the general mass, and yet of possessing 

 the power of individual life and further growth. Some 

 plants propagate themselves by throwing off subordinate 

 zooid clusters of this kind ; and the clusters are then 

 called bulbs. Nearly every kind of perennial shrub and 

 tree may be artificially multiplied after a similar fashion, 

 by removing analogous zooid clusters as cuttings. 

 Cuttings are only artificially-produced bulbs." 



It would be a vain attempt to show the manner in 

 which this principle is applied, unless we were able to 

 reproduce the woodcuts (admirable ones, by the way) 

 with which the little volume is abundantly illustrated. 

 All we can do is to select a passage or two, tolerably 

 complete in itself, which we hope will not only prove 

 instructive but induce the reader to consult the work 

 itself. 



Everywhere the first warm breath of spring arouses 

 into life countless myriads of minute plants, whose pre- 

 sence is only ascertained, in the absence of the micro- 

 scope, by the green colour they impart to stagnant 

 water. They are thus described : — 



" There is a little water plant known under the learned 

 name of the Protococcus pluvialis (< primeval grain of 

 the rain *), which consists of nothing more than a thin 

 filmy wall rolled round into a riobular form, and con- 



multip 

 curiooa 



Thecotfaaji 

 nstead t ^^ 



lntw *lk 



an illustration of one of the modes of cell muitiDrS? 

 already described. But sometimes a very ' ^ 

 is made in these ordinary proceedings, 

 cells become oval or pear-shaped " 

 globular, and a pair of delicat 

 developed at one end. So soon as, ^^ c aill ^ 

 fected they begin to wave backwards and forward* !* 

 incessant motion, and create a great turmoil in the 2 

 chamber where all was so calm before. At lenti!? 

 parent vesicle, unable to stand this internal buS 

 longer, gives way before it, and bursts, and in 



e cili 



s 



tain* 



•7 



progeny swarm away into the open water, tmm. 

 rowed by the vibrations of their ciliary oan ~wE 

 these ciliated cells are observed soon after 



T-liovr Irkrvl- ir«T»\r miir*l~t lilrtk lnAientnal nnlm.l. I 



they look very much like infusorial animalcules. W 

 however, a change comes over the spirit of the mS^Zj 

 dream. The elongated vesicle plumps up into iM^ 

 outline, its oars drop off, and it is a motionless an| 

 a simple unicellular plant in every particular like to %% 

 parent. Its day of roving is past, and its period far 

 settling come. The vibratiie oars are merely % 

 rary expedient provided for enabling the 'piiami 

 grain ' to flit to some distant locality, in order thti 

 may deposit there its vital germs. This coriooipiv 

 ceeding is a plan expressly provided for difWw tht 

 race of this vegetable monad through the nte* 

 Science, ever so free with names, has found 1 iwj 

 appropriate appellation for these ciliated vesicle! TW? 

 look like little animals, while performing their rqid 

 evolutions in the water, and they obviously answer the 

 purpose of seeds, which, wafted by the wind, transport 

 the parent species to remote situations. They are ha* 

 termed ' animal seeds,' or, in the Greek font 

 8 zoospores * (from zoom, an animal, and speiro, to so?). 

 Sometimes the first progeny of zoospores produea 1 

 brood like to themselves, instead of losing their oanal 

 settling down. Then it is this second zoospore gwn- 

 tion that matures into the globular condition, a) 

 becomes the staid and stationary creature." 



In another place we have the following gripkit 

 explanation of the reproduction of the green-fly, 1% 



or aphis. 



* One of the best known of the blighting para 

 the aphis of the Rose. There are few persons who taw 

 not, at some chance time or other, been mo}<* by 

 seeing the stalk of one of their favourite flowers of jte 

 completely ensheathed by a covering of little gwo «• 



possesses a round, plump body, supported on six 

 legs, and furnished with a pair of respective tta» 

 projecting out in front, and two oddly-shaped spm 

 protruding behind. The plump green body is 

 to overflowing with sap extracted from tne F» 

 Pliny's 'saliva of the stars/ and ihe <honef-dew * 



i.u™*;~ Q ;« mA r^v tho su ner abundance or ^ 



resW 5 



into which it has been stowed, me apu» » -— M £ 

 the extreme of philosophic indifference to sarr^* 

 things. It seems to live only to eat and to w -g 

 and not quite to have made up its owiiinmdas J 

 is the better fate of the two. It takes no tojj^ 



goes on tapping the leaf be 



turn 



quaffii< 





Ladv 



the grubs of. the lacewing flies mi) gotten £e£ 



the fuicy aphides as boys do r^ff^ «£ 

 " Through the early summer tbe cw ^. 

 aphides are" wingless ; but later in the ^ %|rf 

 appear in their grazing flocks j, who h»e JJT 

 wings stuck rigidly and proudly uf t«m 

 Now these winged aphides are, 1*« *" 5 id- h# 

 males and females of the species. iw +» 



form the great bulk of the colonies and tfla^ ^ ^ 





the cue 



en i 

 tbe 



00 



.ffi 



i*a* 



history under consideration 



The fa** * Li 

 history under consiu««— »• um byfV 



vesicle of the aphis is deposited as an suajnjer *«J 



the winged females at the close ot a. ^ <&* 



snug nook formed by the union of » •—•f 

 stem. This egg is hatched to there g 



spring 



grub. 



s a wing-^, 



> ne * St* 



after a few days she g*"J^^V *f^J^ 

 ,_ _._ . L. i;b« tn herself ** d lD b*JT 



^ration ^tj^ 



awu 6«*~» ■»—■ .^ ' v are not ony i^f 



grubs? who thus, strange to f say, »« ^ h , T e ^ 



lut really must have ^.[f^eren *** * 



existence, in a phj«^«f "^ **%£* 

 mother was born. The only P* w ^ «*~ 

 ,ed must have been handea 



soon"gives birth to another g^ e ^ t W ^^ 



receiv 



