144 Dublin Microscopical Club. 



(saj- about yxrVij ^^^^ ™ diameter), orbicalar, pellucid, contaioing 

 one or two large chloropliyll-corpuseles, of elongate, somewliat 

 kidney-shaped figure and smooth outline, and seemingly homo- 

 geneous texture, lying up against the periphery, thus leaving the 

 centre more or less clear ; the pseudopodia radiating in every direc- 

 tion, not very numerous, straight, very slender, long (say twice, 

 thrice, or four times the diameter of the spherical body-mass), 

 hyaline, clear ; the outline of the body-mass sharp and smooth, 

 not showing any pulsating vacuoles, nor allowing any nucleus 

 to be detected. If a nucleus were present it might be supposed 

 to be readily enough perceived in a body so clear as this, for 

 even (now that we know that it is there) in the comparatively 

 opaque and granuliferous body of Act'mophrys sol, in certain 

 examples, he thought it was not very difficult to detect the 

 presence of the nucleus, even without dyeing. But the examples of 

 this new form in the gathering were so few and far between, Mr. 

 Archer had had no opportunity of experimenting to test the exis- 

 tence of a nucleus, Jfo doubt the habit and appearance of this 

 very minute form was that of a Heliozoon ; but had it really no 

 nucleus, what would it really be ? Again, could it be possible that 

 the very hyaline pellicular exuvium shown at last meeting has any- 

 thing really after all to say to this organism ? Could it be really 

 possible that on becoming encysted it did not withdraw the pseudo- 

 podia, but became coated (body, pseudopodia, and all) in such a 

 spinulose filmy envelope as that drawn attention to at the last 

 meeting ? If so, when the living protoplasmic substance withdraws 

 therefrom, so as to leave behind the " spore-like " spinulose exu- 

 vium, the pseudopodia must pull themselves out of their minute 

 tubular investments, and then escape (by a rent ?) from the central 

 globular portion. Is this pellucid integument composed of cellu- 

 lose ? All this would be very remarkable, and seems to indicate that 

 this organism is at least most probably not a Heliozoon, much as it 

 simulates one, but a Sarcodine of •' lower " type. It is possible the 

 great sharply- defined chlorophyll-masses might at some epoch 

 become " zoospores " and perhaps " conjugate ; " but this is only 

 supposition, Mr. Archer learnt that Prof. Lankester was making a 

 thorough examination with large material of this form, and it was 

 to be hoped that he might be able to throw much light upon it. One 

 thing at least was certain, that this was not the same green " Helio- 

 zoon " referred to by Mr. Archer at last meeting. At any rate, 

 this is undoubtedly a new form ; and Mr. Archer felt greatly indebted, 

 so far as he was concerned, to Prof. Lankester for the honour done 

 him in connecting his name with so interesting a novelty. He had 

 also to thank Mr. Bolton very much for his courtesy and the pains 

 he had taken to cause him at last to see the right thing. 



A modified Microtome exhibited. — Dr. Scott exhibited a microtome 

 devised by Dr. Hayes, Merrion Square, mainly on the model of the 

 instrument by Junge of Heidelberg ; but in place of the very great 



