• On the Corpuscles of the Blood. 321 



2. Such having been my views, it was very satisfactory to 

 meet with the following confirmation of them. In a lecture 



delivered a few weeks since at the College 

 of Surgeons, Professor Owen exhibited the 

 sketches 6 to 10, in a thesis by Dr Baggc,* 

 representing successive stages in the de- 

 velopment of the ovum of an intestinal 

 worm ; and stated the results of Dr 13ag- 

 ge's observations. I find the following re- 

 marks on this subject in the published lec- 

 ture of Professor Owen : — " There is a close 

 and interesting analogy between the above 

 phgenomena [observed by Dr Bagge, fig. 6 

 to 10] which were published in 1841, and 

 some of those communicated by Dr M. Barry to the Royal 

 Society, in January 1841, and published in the Philosophical 

 Transactions of the same year. The clear central nucleus of 

 the blood- corpuscle is there shewn to form two discs, t vvhich 

 give origin to two cells. We may, likewise, discern in the 

 pellucid nucleus of the yolk, dividing and giving origin to two 

 yolk-cells, according to the German author, the hyaline nu- 

 cleus of Dr M. Barry." t 



3. Professor Rudolph Wagner observed that the size of the 

 blood-corpuscles in the naked Amphibia is *'so much the 

 larger, the longer the gills continue in the larval state." Thus, 

 the blood-corpuscles are larger in the Newt than in the Frog. 

 He hence conjectured that the Proteus and Siren, because 

 they permanently have both gills and lungs, — ^being therefore 

 permanently larvix^, — would be found to have the largest blood- 

 corpuscles. In the Proteus, he had the opportunity of seeing 

 the idea realized. § — This connexion between the size of the 

 blood- corpuscles and a larval condition of the animal, I believe 

 has not been explained. 



* De cvolutionc Strongyli auricularis et Ascaridis acuminatce viviparormn, 

 Erlangaj, 1841. 



t See Phil. Trans. 1841, pi. 18, fig. 37, [and pi. 17, fig. 24.] 



\ Hunterian Lectures, by Professor Owen, F.R.S,, from Notes taken by W. 

 AV. Cooper, M.R.C.S., 1843, No. 3, p. 78. 



§ See Proceedings of the Zoological Society, Nov. 14, 1837. 



