320 



KNOWLEDGE. 



August, 1911. 



The temperature of the sea was higher than in the corres- 

 ponding week of 1910, and the individual readings varied from 

 52° in Scotland to 67" at Margate, and 70' at Seafield. 



During a kite ascent from Pyrton Hill on June 14th. the 

 sky was o\ercast, but though the kite ascended to a height of 

 over four thousand feet, the clouds were not reached. On 

 this occasion the direction of the wind was found to be the 

 same throughout, but its \elocity steadily increased with the 

 altitude. The humidity of the air also increased with the 

 height from 70% at the ground to 95"o at four thousand feet, 



MICROSCOPY, 



By A. \X. SHEPP.iRD. F.K.M.S.. 



witli tlic assistance of flic foUoiciiiii tiiicroscopists : — 



.Arthur C. Banfield. Arthur Earland. F.R.iM.S. 



The Rev. E. \V. Bowell. iM..A. Richard T. Lewis. F.R.M.S. 



Ja.mes Burton. Chas, V. Rolsselet. P^.R.M.S 



Charles H. Cakfyn. D. J. Scourfield, F.Z.S., F.R.M.S. 



C. D. Soar, F.I...S., F.R.M..S. 



HVDRACAKINA OF CLARE ISLAND.— The Royal 

 Irish Academy has just published part 39i of the Clare Island 

 survey. This paper, to any one interested in the Hydracarina 

 of the British area, will prove most valuable. The results of 

 the survey will be published from time to time, as the different 

 experts who have undertaken to work at their own particular 

 group finish their reports. These reports will not only 

 contain the flora and fauna of the island, but the history and 

 geology of the district, and will be published in sixty-seven 

 parts, four' only of which are ready, Mr, J, N, Halbert, of 

 the National Museum, Dublin, undertook, and has finished, the 

 Hydracarina, and he has done it well. It is. I think, the best 

 paper yet published on the water mites of the British area, 

 both as regards the te.\t and the figures. Mr, Halbert has 

 added four new species to science : Eylais rclicta, 

 Frontipoda Carpeiiferi, Atractldcs brcvirostris and 

 L'tiionicola riiuilaris. Besides the above he has also added 

 twelve species previously recorded on the continent only, 

 -Altogether, Mr, Halbert records eighty species, representing 

 thirty-one genera, which, with the sixteen additional ones now 

 added by Mr, Halbert, gives us two hundred and thirty species 

 of Hydracarina, representing sixty-one genera, for the British 

 area, Hydrysphantcs placationis K, Thou, which Mr. 

 Halbert asterisks as a new record, has been already recorded 

 by Mr, W, Evans in 1909, for Scotland. See Proceedings 

 of the Royal Physical Society of Edinburgh, \'ol. XVH, 

 page 42. 



There is one mite Mr. Halbert mentions «hich I am not 

 sure is correctly named on pa,ge 37 ; he mentions Arrhenurus 

 triciispidator, O. F, Miill,, Achill Island. June. "The mite 

 recorded here is the A. bicuspidator (Koenike) 12. and other 

 references." Now Koenike, in 12, Acarina Milben Brauer, 

 Die Siisswasscrfauna Deiitschlands, Heft, XII, 13-191, 

 Figure 1, 277. 1909, gives both .4. tricuspidator Miill. and 

 .-1. bicuspidator Berlese, and there is no mistaking the two 

 mites. The petiole of Miiller's Figure Plate iii. Figure 2, in 

 his Hydrachnae, 1781, is certainly rounded on the extreme 

 posterior margin, but in Berlese's -4. bicuspidator the margin 

 of the petiole is curved inwards. I have both mites myself. 

 What I take to be the real .4, tricuspidator Miill, was 

 recorded by Dr. George, for Britain, in 1901, as ,4. niaxiinns 

 Piersig, Science Gossip, 1901, page 230. 



One of the most interesting finds is Frontipoda 

 carpentcri Halb, as previous to this we only knew one 

 species of this genus, F. niusculus Miill. Another is the 

 addition to the genus Atractides. Mr. Halbert gives a very 

 useful synoptical table for the determination of species. 

 There are three plates of well-drawn and well-produced 

 figures, giving the absolutely essential details for identification 

 of the species. Take it all round it is a most interesting 

 addition to the l^ibliographv of fresh-water mites, 



Chas, D, Soar, F.L.S., F.R.M.S. 



HYDRCRUS FOETIDUS VILL.— Recently I had the 

 good fortune to come across the above, and as it is in sexeral 

 respects a singular and interesting plant, it may be worth 



while bringing it forward in a short note. The first point 

 about it is that it is decidedly rare in this country. Professor 

 West says, "It is of very rare occurrence in the British 

 Islands, being known only from Yorkshire and Scotland," But 

 " it is common in central Europe and in the Arctic regions 

 when the snows melt in spring," I found it in great abund- 

 ance in a coinparati\ely quiet backwater, in a rapid stream of 

 ice-cold water rnnuing down towards the Mer de Glace, at 

 Chamonix. It was attached to the rocks and stones, and was 

 plentiful on a rock forming the edge of a small cascade. To 

 the naked eye it looks like a dull-coloured moss, or 

 one of the filamentous algae ; the filaments attached at 

 the base, floating free and swaying in the stream. Its 

 specific name foctidus is appropriate, as it has a most 

 unpleasant smell, resembling that of stale fish. The 

 " Micrographic Dictionary" styles it "a genus of Confervoid 

 algae " but at the same time points out its obviously 

 true relationship, which is with the very simplest of 

 the algae, the Palmellaceae, Probably there is not more 

 than one species. Professor West calls it Hy drums foetid us ; 

 Cooke, H. penicellatus, and mentions a variety. The fila- 

 ments vary in size from quite small ones, up to a length of 

 several inches. They are of considerable thickness, and 

 simple at the base, while above they are densely branched, the 

 branches often thickly covered with minute outgrowths and 

 fibres, giving the whole a very moss-like appearance. Dr. 

 Cooke has a drawing — " British Freshwater Algae," Plate 10 

 Figure 4 — which exaggerates this a good deal, unless his 

 illustration was taken from another variety. One would 

 naturally expect the stem and branches to consist of cells with 

 definite walls like other plants, but they do not. The whole is 

 formed of a more or less tough gelatinous sticky substance, 

 without any apparent structure under the microscope, and in Ihis 

 are embedded numerous minute olive-green bodies. They are 

 packed closely and are somewhat globose in the branches, with a 

 tendency to become mis-shapen and angular owing to pressure, 

 while in the stem they become oval and elongated, or even 

 comma-shaped, and are arranged partially in lines. They do 

 not seem to have a definite wall ; Dr. Cooke says it is difficult 

 to distinguish one ; Professor West says there is none. It is 

 of course, these very small bodies that give rise to the 

 gelatinous moss-like structure, and except for the peculiar 

 form — a chance resemblance to that of a much more highly- 

 developed organism — the relationship to such plants as 

 Tetraspora. Sphaerocystis andPalniodictyon, which we find 

 constantly in our own waters, would be evident. Professor 

 West tells us " the entire structure behaves almost as a 

 multicellular plant, growth in length being entirely dependent 

 on single apical cells." He classes it with the Phaeophyceae, 

 but its affinities seem to me much more with the simple 

 genera named above, than with the highly-developed and 

 specialised brown sea-w-eeds. Reproduction takes place by 

 means of peculiar-shaped zoogonidia, developed from the 

 colom'ed bodies in the branches. The filamentous form and 

 minute branches and fibres are probably only an adaptation to 

 the circumstances under which the plant exists. Were it not 

 attached firmly to the rocks and stones, and of a form which 

 gives only slight resistance to the stream, it would soon be 

 washed away in the rapid torrents in which it dwells. Cold 

 and violent mountain streams are not favourable dwelling 

 places for most Algae ; it is hardly worth while looking for 

 them there, and this e.xample is remarkable on that account as 



well as for its singular structure. 



J. B. 



THE MICROLOGIST.— We have received from .Messrs. 

 Flatters. Milborne and McKechnie, Ltd., the July number 

 (Part v.), of their little iiuarterly journal. Tlie Micrologist. 

 As usual it is well illustrated, there being twehe text figures 

 and three plates of figures reproduced in half tone. The first 

 article is by Mr. Gordon A. McKechnie, and is devoted to the 

 Porifera (spongesl. A short account is given of their structure, 

 classification and life-history, which is followed by details for 

 the preparation of slides illustrating the histology of the 

 different types. The slides, six in number, sent out with this 

 part all illustrate sponge structure. Transverse sections of 

 Grantia conipressa, Euspongiii officinalis. Hiilichcinilnu 



