24? Mr. G. Gulliver's Observations on the Blood Corpuscles 



propose to give an account of the blood corpuscles of such 

 animals as I have had an opportunity of examining. Of many 

 of these particles I believe no description has hitherto been 

 published ; and some others which have been previously de- 

 scribed I have examined anew with a view to more accurate 

 comparisons. I am not aware that the peculiar form of the 

 corpuscles in certain species of the genus Cervus has been 

 hitherto observed in any class of animals. 



The general results appear interesting to me in many points 

 of view, particularly in respect to certain differences in the 

 size of the corpuscles in the same individual at different pe- 

 riods of existence, as well as in nearly allied species of the 

 same genus ; and the resemblance, on the other hand, of the 

 blood disks in some groups of the animal kingdom. The 

 connexion, too, between the size and form of the blood par- 

 ticles and the respiratory organs, 1 have found to be remarkable. 

 But before entering into conclusions it will be necessary to give 

 the observations in detail, reserving a summary arrangement 

 of them, and the deductions which they appear to warrant, for 

 a future section of this memoir, when an opportunity will be 

 afforded of reference to the Jabours of others in this field. 



The instrument made use of in these observations is a com- 

 pound microscope, with an achromatic object-glass of one- 

 eighth of an inch focal length, made by Ross, and furnished 

 by him with a micrometer eye-piece divided into spaces cor- 

 responding to 1 -4000th of an inch. The magnifying power 

 afforded is exactly 800 diameters with a clear definition. 



If one space and a quarter of this micrometer were occu- 

 pied by a single globule, this would of course measure 1-S200th 

 of an inch; if three equally-sized particles lying in a line, 

 and touching at their edges, covered three spaces and a half, the 

 diameter of each of these would be l-S^SQth, — if four spaces, 

 l-3000th of an inch. Now these measurements are mentioned 

 because they are very frequently obtained from the average- 

 sized human blood disks, which are to be distinguished from 

 the remarkable varieties which Mr. Bowerbank has observed 

 among them, and which I have also witnessed, though I think 

 in a less degree than he mentions, in man and various ani- 

 mals. In the human blood corpuscle, the diameter last 

 mentioned is not so common as the two former. In the ab- 

 solute accuracy of any micrometer applied to objects so ex- 

 tremely minute, it is difficult to place implicit reliance ; but 



avoid acknowledging the kindness and urbanity of Mr, Ogilby, who enter- 

 tained my application with his usual zeal in the promotion of zoological 

 inquiries. I have also repeatedly been indebted to the kind assistance 

 of Mr. Youatt, the excellent medical superintendent of the Gardens. 



