30 



Aj)nl 5th, 1877. 



Structure of the red £Iood-corpuscIe of Fishes. — ITr. Hammond, of 

 Milton Chapel, referring to liis exhibition at the last scientific 

 meeting, now presented drawings in illustration of the stmcture of 

 the red corpuscles as shown while they were flowing within the 

 minute blood-vessels of the yplk-bag of young trout, which had 

 been hatched about a week fi-om its eggs, in which the part was so 

 transparent, and the fish so lircly, that the circulation of the blood 

 could be easily seen under an objective of half of an inch focal 

 length. And when the red coi-puscles were moving slowly, each of 

 them wore seen to contain a distinct nucleus, projecting on both 

 sides of the corpuscle when it was seen on edge, and appearing 

 equally plain when the coi-puscle presented its broad surface to the 

 eye of the observer. The facts were so plainly seen as to admit of 

 no doubt of the existence of a nucleus in the living red blood- 

 corpuscle of fishes, and thus far to settle a much disputed and 

 obscure point ; for it has been asserted on high authority that the 

 nucleus is not found till after tlie escape of the corpuscle from the 

 living animal, and is indeed purely a post-mortem phenomenon like 

 the coagulation of the blood. This is the view of an eminent Britisli 

 physiologist. Professor Savory, F.E.S , whose memoir on the subject 

 appeared in the "Proceedings of the Eoyal Society, March 18th, 

 1869, and has been generally accepted as conclusive in favour of the 

 opinion that the nucleus does not exist in the living red blood- 

 corpuscle. Only Professor Gulliver, F.E.S., was so far from being 

 convinced that, he, in his " Observations on the sizes and shapes of 

 the red corpuscles of the blood of Ycrtebrates," published in the 

 "Proceedings of the Zoological Society," June 15th, 1875, states 

 emphatically that he has " plainly seen in certain fishes the projec- 

 tions on the corpuscles, indicative of a nucleus, while they were 

 flowing within the living blood-vessels" (p. 478). Thus, however 

 truly Professor Savoiy's observations may have laeen made on frogs 

 and newts, his conclusion that " the red corpuscle of all verbetrates 

 is, in its natural state, structureless, and that, when living, no dis- 

 tinction of. paits can bo recognized, so that the existence of a 

 nucleus in the red coi-puscles of Ovipara is due to changes after 

 death or removal from the vessels" (pp. 340-350), is directly 

 opposed by Mr. Hammond's observations. The question is import- 

 ant ; for although the physiological import may be obscure, its 

 taxonomic significance is so signal as to form the foundation of Mr. 

 Gulliver's division of the vertebrate sub-kingdom into the two great 

 sections of Pyrenaemata and Apyrenaemata, as explained and illus- 

 trated by a plate, in his paper above cited. 



