545 



the means of growth and increase from the fluid portion of the blood ; 



and afterwards, when they have become fully developed, undergo 

 dissolution, and help to supj^ly the waste of the fluid that has been 

 expended on the nourishment of the diff'erent structures, leaving 

 other little bodies, which also undergo development, to assist in the 

 further elaboration of this fluid. He states also, that the develop- 

 ment of these latter bodies appears to have a certain relation to the 

 type of each particular class of animals ; and remarks that in the 

 vertebrata the size of the corpuscle is perhaps in a ratio inverse to 

 that of the activity and extent of the function of respiration. 



The author states that he has been led to these views, which ap- 

 pear to him to apply to animals generally, by an examination of the 

 corpuscles, and by w^atching the changes which take place in the 

 blood in lepidopterous insects ; and he points out their accordance 

 with those of Wagner, Henle, and Wharton Jones, with regard to 

 the function of the corpuscles ; but proposes to give the details on 

 which his own view respecting the size of the corpuscle is founded 

 on a future occasion. 



He then enters more particularly on the consideration of the forms 

 of corpuscle in the blood in the Articulata, which he marks as four ; 

 although, he observes, they are in reality only so many stages of 

 development of one ultimate structure. These forms are, — first, the 

 molecules, which he regards as comparable to the molecules observed 

 in the chyle of Vertebrata by Mr. Gulliver; secondly, the nucleated 

 or oat-shaped corpuscle, which he believes w^ith Wagner are analo- 

 gous to the white, or chyle corpuscles of Vertebrata ; thirdly, the 

 spherules, or minute rounded bodies developed from the oat-shaped 

 corpuscle, and which he believes are analogous to the free nucleoli 

 of Valentin, and probably to the very minute white, opake granules 

 constantly observed in the blood of vertebrata; and lastly, \he discs, 

 which are further developments of the spherules, and analogous to 

 the true red blood-discs of the higher animals, and which, as he 

 states in a subsequent part of his paper, in his examination of the 

 blood of the human foetus, he believes that he has also traced from 

 the white, opake granules or spherules. 



The author then proceeds to describe these forms of the corpuscle 

 in insects more minutely, and enters into considerable detail wdth 

 reference to the oat-shaped corpuscle, tracing it from its earliest 

 distinct form, before any nucleus is perceptible in it ; and shows that 

 the nucleoli which constitute this body are gradually increased in 

 number, until the corpuscle has attained its full size, when it first 

 changes its form and becomes shorter, then rounded, and afterwards 

 entirely breaks up and liberates the nucleoli that have been deve- 

 loped within it. This change of form he shows always takes place 

 very rapidly in all the oat-shaped corpuscles, large and small, when 

 out of the body, and to this circumstance he attributes the diversity 

 in the descriptions that have been given by various observers of the 

 form of the corpuscle. He shows also, that, with reference to the 

 function of this body, the corpuscles are usually found in greatest 

 number during the act of breaking up, immediately before the larva 



