SUMMARY OK CUKKEN'I RESEARCHES RELATING W 



Hi, bowever, appears to be more or less personal, and probably 

 8 ome extenl upon the observer's power of stereoscopic pei 



Quekett Microscopical Club. The 472nd Ordinary Meeting of the 

 Club was held on March 28, L911, the President, Professor E. A 

 Vlinchin, in the Chair. Mr. A. 0. Banfieid exhibited and described a 

 new form of mercury-vapour lamp made by the Brush Electrical < lompany. 

 sua! type of lamp takes the form of a luminous cylinder about 

 7 feet in length, giving a great total luminosity with a relatively low 

 specific intensity. In the new form, the use of fused quartz for the 

 manufacture of the tube enables the length to be reduced to about 

 I inches, although the candle-power, about 3000, remains the same, and 

 the gain in bhe specific intensity is so enormous as to render it eminently 

 suitable for microscopic use. The peculiarities of the mercury spectrum 

 were referred to, and the great advantages offered by this illuminant 

 were pointed out. A paper on "Dark-ground Illumination," by Mi 1 . 

 E. M. Nelson. F.E.M.S., was read by the Honorary Secretary. The 

 author referred to the increasing use of this method of illumination. 

 The form of lamp recommended — paraffin, with i-incb wick — was 

 refem d to, and the best means of obtaining dark-grounds described in 

 detail. Owing to the lateness of the hour, a paper on "Some New 

 Diatomic Structure Discovered with a New Zeiss Apochromat," commu- 

 nicated by Mr. A. A. C. Eliot Merlin, F.R.M.S., was taken as read.* 

 Mr. .lames Murray, F.R.S.E., F.Z.S., made some introductory remarks 

 to a paper on "Water-Bears, or Tardigrada," intended to supplement 

 bhe one contributed in 1907. As the name Tardigrada is already appro- 

 priated by Vertebrates, the new official name of the group is order 

 Arctiscoida, family Xenomorphidse. Four new genera were described, 

 and their relationships and those of the other genera discussed at some 

 length, and the paper concluded with a synopsis of the ten genera known 

 and the 120 at present admitted species. A bibliography is appended. 



Tin 473rd Ordinary Meeting of the Club was held on April 25, 1911, 

 the President in the Chair. Mr. A. C. Coles, M.D., D.Sc.Edin., etc.. 

 sent a note describing the use of Parolein as a mounting medium. It 

 is absolutely neutral, and, so far as is known, is entirely without action 

 on any dyes, lis refractive index is 1 , 471, as against 1-530 for balsam 

 in xylol. The President exhibited and described preparations of two 

 of cysticercoid of rat-tapeworms from the body-cavity of the 

 rat-flea, Ceratophyllus fasciatus. These were Hymenolepis diminuta and 



obably) //. murina. He also showed dissections of the ventral 



nervous system of the flea, Ceratophyllus fasciatus, and the salivarj 



inde and duct of the same organism. Mr. N. E. Brown contributed 



- Some Odd Note.- upon Seeds," describing some of the more beautiful 



ms he had noticed. He recommended lighting the mounts with a 

 apot-lens and concave mirror from below, and also with a stand-condenser 

 from above, the combined lighting being very effective. The use of 

 coloured gelatin, say red, placed below the spot-lens, and a piece of green 

 placed over the stand-condenser, still further increased the beauty of 



* Jouru, Quekett Micr. Club, April 1911, p. 181. 



