500 



THE GARDENERS' CHRONICLE. 



[JULl 



» od the dan-ling stalk of the catkins. These male worsted threads and beta* given gradually in place of a 



flowers are destined to wither and drop off as soon as 

 their office of shedding the pollen is terminated ; but if. 

 before they have done so, they are seized and appropriated 

 by the fly, they become permanent, and remain so until 

 the maggot within the gall ceases to feed." From my 

 o*n observations, as already recorded, it appears that 

 many of the galls remain after the larva has become a 

 pupa, and the same happens with the Woolly-galls, which 

 are produced, as was lately shown, upon the male cat- 

 kins of the Oaks ; and the same difficulty presents itself 

 in both instances relative to the deposition of the eggs 

 by the summer broods, as we recently intimated, and 

 which at present has not been satisfactorily accounted for. 

 These Cynipidce are not free from the attacks of para- 

 sites, for Ibred two very brilliant species from the cur- 

 rant-galls : one was apparently the Callim<»me flavipes of 

 Walker, which is of a beautiful green with yellow legs, 

 the ovipositor of the female heing longer than the body ; 

 the other was the curious Platymesopus tibialis of West- 

 wood. I am also now able to state that a pretty parasitic 



rush of steam when hot flues are watered, it more re- 

 sembles tbe natural moisture of the air, and is more 

 healthy for the plants, and the moist air may be con- 

 tinued for any number of hours at a time, without any 

 trouble to the gardener, exactly as he wishes it, and to 



any degree. 



" The house ha<* only been built, two seasons, but the 

 strength and healthiness of the wood of the Vines and 

 foliage exceeds any in the neighbouring hothouses, or 

 indeed in most others, and the bunches of fruit are 

 quite magnificent. Much less fuel is required through 

 the year — nearly a half — and less attendance. There is no 

 chance of a flue choking, as there are none, or of a pipe 

 bursting, as there are none ; of course the original cost is 

 saved, and the repair necessary for both avoided ; the fire 

 is made up at night, and requires no attention until morn- 

 ing. The stove used is one of Haydon's patent stoves; and 

 the idea occurred to me of using it for a hothouse, from 

 having heated a large church with a stove by the same 

 maker — merely a circulation of hot air, without flues or 



Chaloidideous insect has been produced from one of the pipes. Several professional gardeners have visited the 



Woolly-galls ; several of both sexes were discovered in 

 the box the 4th July, and they seem to be the Eulophus 

 (Prosorus) similis of Walker.* 



It will be remembered that the conglobated masses of 

 twigs on the branches of the Birch, resembling swarms 

 of bees and magpies' nests at a distance, also the mossy 

 excrescences formed on the Briers, are the work of simi- 

 lar insects ; which lately led to the suggestion, that if 

 we knew the acids or poison which produce such remark- 

 able objects, and the exact manner in which they are 

 applied, it might be in the power of the philosopher to 

 experimentalise with the same materials, and produce 

 vegetable curiosities as interesting and ornamental as the 

 Weeping Ash, &c. Let it not, however, be imagined that 

 we prefer monstrosities to the simple beauties of nature, 

 but every natural curiosity is worthy of investigation, 

 if it be only in the search of truth ; to unveil the mys- 

 teries of the creation appears to be one of the intermi- 

 nable subjects destined to exercise the ingenuity of man. 

 — lturicola* 



house lately, and all have approved of the great simplicity 

 and cheapness of the plan ; and from the success attend- 

 ing it, there is no doubt of its being generally adopted: 

 and the more so, as it is well known that the fruit is 

 always higher flavoured when a free circulation can be 

 adopted of fresh air, at a proper temperature ; indeed, 

 the fine bunches of fruit which were obtained last season 

 were particularly high flavoured. The size and strength 

 of the Vines are more like the growth of five years than 

 two, and the foliage is in proportion." — W. Murray. 





PLAN OF A HOTHOUSE AT POLMAISE, 



STIRLINGSHIRE. 



We have been favoured by Mr. Murray with the fol- 

 lowing plan and description of a hothouse, lately erected 

 by that gentleman at Polmaise, and heated without the 

 intervention of flues or hot-water pipes, but merely by a 

 circulation of air from the hot-airj chamber of a stove, 

 behind the wall of the hothouse. Mr. Murray writes 

 that " The hot-air is mi.de to circulate freely through all 

 parts of the house, at any temperature the gardener 

 chooses, and a constant fresh circulation of air is kept 

 up, by merely taking advantage of the well-known prin- 

 ciple that hot air is lighter than cold air, and that there- 

 fore a circulation can easily be kept up by making the 

 openings or drains one at each corner of the hothouse, 

 and placing a grating on them, and conducting the drains 

 under the surface of the earth of the house, into the 

 stove placed at the outside of the back wall of the 

 house, and introducing the air when heated in the 

 hot-air chamber of the house, by means of an 

 opening «s low as possible through the back wall, 

 into the house ; but as the air of the house would 

 soon be all returned hot into the house, two drains,' 

 one at each end of the house, are made, convey- 

 ing fresh air also into the stove, and uniting with the 

 two from each corner before entering the stove, and 

 thus keeping up a complete supply of fresh air to the 

 stove to come out heated air, to supply air to the plants 

 in constant succession, and thus forming a healthy 

 climate at any temperature the gardener wishes, with 

 a constant circulation, but without any chance of in- 

 juring the Vines at any stage of their growth from the 

 admission of cold air. 



"In order to steam the house, a very simple process is 

 adopted, by placing a woollen cloth along the whole 

 length of the house before the hot-air chamber's opening, 

 and watering the woollen cloth, thus producing a mild 

 and gentle steam without any risk of its being too hot, 

 as often happens when a flue is overheated and then 

 watered. A stage for flower-pots is placed in front of the 



10 



15 





\ 



Rkkkrencr to Plav. 

 A. The Grating-, where the cold air is admitted to the stove 

 from within the house. 



B* The Drain, conducting the cold. air to the stove, over which 

 is the gangway. 



C. A Valve for admitting fresh air from without, keeping a 



healthy atmosphere within. 



D. The Stove. 



E. The Warm Air Chamber, and e the outlet from the chamber. 

 V. The Woollen Cloth nailed underneath a stajje for plants 



which extends to within 2 feet from each end of the 

 Vinery, dispersing the warm air equally through the 

 Vinery, and steaming it by applying water through the 

 rose of a watering:- pan upon the cloth. 

 G. Steps into the Vinery. 



the subject received lately from Mr. J. Henderson, who 

 woollen cloth, which is stretched along the back of the nas P^id so much attention, to these beautiful plants and 



HYBRID FERNS. 



A translation of some remarks on Hybrid Ferns, 



by E. Regel. in the M Botanische Zeitung " of August 1 1 , 



1843, may be acceptable to some of your readers ; to 



these I have appended copious extracts from a letter on 



stage sloping towards the back wall, the stage being about 

 three feet at the bottom and 9 inches at the top. Indeed, 

 the watering the woollen cloth has been found so bene- 

 ficial a way of applying steam that some of the neigh- 

 bouring gardeners have applied it over their flues, and 

 watered it in place of watering the hot flue as formerly. 

 I have also adopted another method of steaming the 

 house, so producing a damp atmosphere, which is prefer- 

 able. A sewer for conducting water runs along the 

 upper board of the above-mentioned stage, and into the 

 sewer are inserted worsted threads, which hang down a 

 few inches on the woollen cloth— sav five or six inches— 

 and convey water gradually and constantly by means of 

 the capillary attraction, thus keeping up anv degree of 

 moisture m the house that may be required, which is 

 particularly beneficial during the swelling of the fruit, 

 and can be regulated completely by the number of 

 threads employed, and their thickness ; and the water in 

 the sewer is supplied from a small barrel standing at one 

 end of the stage, which can easily be filled when re- 

 quired ; any degree of moisture may thus be given to 

 the air of the house by increasing the quantity of heat 

 and proportioning the supply of wa ter through the 



* Several of these genera are illustrated in Cnrtis's Brit. 

 Ent., vide pi. 133 and 552; also the Guide, Genera, 6i8, 623, and 



630. 



formed so valuable a collection of them. As the ob- 

 servations not only of a scientific but of a practical man, 

 they will, I am sure, be thought worthy of comparison 

 with tiiose of Regel, and the more especially as Mr. 



Henderson had not seen Regel's observations. Regel 

 writes as follows : — 



•' The production of hybrid Ferns was first announced 

 in modern times by Bernhardi. At present it is only 

 in the genus Gymnogramma that such intermediate 

 Ferns have arisen during cultivation, as maybe regarded 

 as hybrids. The arguments which speak for such 

 hybridisation must be but negative so long as nothing 

 certain is known respecting the mode of impregnation ; 

 for the views of Hedwig, StUhelin, CEder, Schmidel, 

 Kblreuter, Gartner, and Mirbel, on the male organs, have 

 been long regarded as unfounded. In like manner 

 Bernhardi's and Presi's views are but hypothetical. The 

 interesting discovery of Spermatozoa in Ferns lately 

 made by my friend Dr. Nageli, and which he will shortly 

 publish, place the matter in a new light. Though the 

 mode of impregnation may not have been discovered, 

 still we have here a possibility of this process taking place. 

 The negative ground, then, which speaks for hybridisa- 

 tion in the geaftg Gymnogramma acquires greater force. 



p species only is cultivated, each species 

 ins constant under cultivation ; d 



So long as as 



i of Gviim* 



■ 





but intermediate forms spring up from seeds whs 

 several sorts are grown. I have in my Herbarium fro 

 the gardens of Berlin and Bonn, the following intermedia 

 forms, which may be regarded as hybrids:— 



"1. Between G.chrysophylla and peruviana, which 

 nearest to G. peruviana, as regards the mode of divisio 

 and delicacy of structure ; but the meal on the under sii 

 is of a somewhat duller \ellow than in G. chrysoph v Iia 

 This species is dispersed in gardens under the name o 

 G. L'Herminieri. Whether it has arisen from culture 

 or has been introduced, I cannot speak with certaiutv 

 it seems, however, to be one of those Ferns which arc 

 apparently hybrids. It was distributed from the Leips'u 

 garden through Germany. 



M 2. I have a plant between G. chrysophylla and G 

 distans, which was raised at theBotanic Garden at Berlin 

 In outline it resembles G. distans, but the pinna? 4n 

 broader, and the colour of the meal is dull yellow. Pro- 

 bably this is the same plant which was raised from seed 

 at Erfurt, and named by Bernhardi G. chrysophylio- 

 distans. 



"3. A third Fern, intermediatebetweenG. chrysophylla 

 and dealbata, is known in Gardens by the name of" Or. 

 Martensii. 



"4. Two Ferns are known to me between G. chrysc- 

 phylla and G. calomelana, both of which agree in outline 

 with G. calomelana. In the one the meal is of a green- 

 ish yellow; this, goes by the name of G. Massoni, and 

 seems to have originated in England. The second ori- 

 ginated in the Bedin Garden, and has the meal as in- 

 tensely yellow as G. chrysophylla. This I call G. chry- 

 sophyllo-melana. 



"5. I have a Fern perfectly intermediate, both as to 

 division and the colour of the meal, between G. distans 

 and G. calonoelaua. It is from the Berlin Garden, and I 

 distinguish it by the name of G. distanti-dealhata. 



11 6. I have two Ferns intermediate between G. dealbate 

 and G. calomelana ; one of which is nearer to th* 

 former, the other to the latter. The first is from the 

 Berlin and Bonn Gardens, and named by me G.dealbato- 

 calomelana; the latter, from Berlin, I call G. calome 

 lano-dealbata. 



"7. Lastly, I have a Fern intermediate between G 

 calomelana and G. distans, from the Berlin Garden 

 which I call G. distanti-calomelana. It is worthy c 

 remark that these supposed hybrids are usually far mgr 

 vigorous and larger than the parent plants. 



" In conclusion, I beg leave to remark that if, in ts&t 

 absence of direct proof, these intermediate Ferns be 

 regarded as mere varieties which have arisen from cul- 

 ture, we must for the sake of consistency suppose all the 

 mealy species of Gymnogramma to have arisen from a 

 single stock, which, if the extreme Ferns be considered, 

 is very difficult to agree to." 



Mr. Henderson writes to me on the subject as follows t 

 — " I am afraid that I shall not be able to give you 

 much useful information about Hybrid Ferns ; it is a 

 very perplexing subject, and all my inquiries in that 

 direction have not enabled me to come to any decided 

 opinion about the matter; Whether these plants are to 

 be regarded as true hybrids,- or the changes which they 

 exhibit depend on peculiar circumstances affecting the 

 individuals so changed, are questions which I think have 

 not yet (as far as I know) been satisfactorily made out. 



" I believe it is only in the genus Gymnogramma 

 that those Ferns which are called hybrids have been 

 produced from spores, appearing to partake of the cha- 

 racters of two ditferent species. Among the hundreds 

 of seedlings which are every year produced here, I have 

 never in any instance observed a disposition to depart 

 from the characters of the parent plant in any except 

 those of Gymnogramma, and even these are confined 

 to species the fronds of which have a farinaceous covering 

 underneath. They differ chiefly in the colour of the 

 farina, in the shape of the frond, and in having a much 

 more robust habit than the species from which they are 

 derived ; they also produce few rather diminutive thecte, 

 with small imperfectlv-formed spores,, which I think are 

 mostlv if not always abortive. I have sent you speci- 

 mens "of the different sorts that have been raised here, 

 and also a specimen of G. Martensii which was raised on 

 the Continent, and which, in " Link's Filices," is said to 

 be intermediate between G. calomelana and G. chryso- 

 phylla. I have aleo within these few days received G. 

 L'Herminieri, said also to be intermediate between these 

 species, but it is evidently much nearer to the latter 



than the former species. 



"No. 1 is between G. chrysophylla and G. sulphurea, the 

 frond resembling the latter species in outline, but on a 

 larger scale, and the farina approaching to the rich 

 golden colour of the former species. Whether this is 

 really an accidental varietv or a species from foreign 

 spores I am unable to say." Two or three seedlings came 

 up here six or seven years ago— one in a pot among 

 foreign seedling Ferns, and another in a pot with an orchi- 

 daceous plant : since then about a dozen more have been 

 raised, all so perfectly resembling one another, that I am 

 inclined to think that it is rather a species than a variety. 

 It is by far the most graceful of all the farinaceous Gymno- 

 grammas.— " No. 2 resembles much G. tartarea, but 

 differs in its very large size, its more upright habit, and 

 in the yellow farina.— M No. 3 bears nearly the same 

 relation to G. calomelana which No. 2. does to U. tar- 

 tarea. It grows to a very large size, nearly twice that 

 of G. calomelana. Neither this nor the preceding have 

 anv resemblance to the species with yellow ' arina «— 

 "No. 4 seems intermediate between G. calomelana ana 

 one that is known in gardens under the name otu. 

 ochracea, a species from Buenos Ay res : the farina is paier 

 than in G. ochracea.— I have a number of seedlings, « 





A 



