236 RED PARTICLES 



amongst all animals, and as their structure is in all animals 

 similar, we are naturally led to conclude that parts so com- 

 plicated cannot be made by a mere mechanical agitation of 

 the chyle in the blood-vessels or lungs, but that nature has 

 set apart certain organs in the body for their formation ; and 

 which we shall next inquire into. 



loss of its vitality on leaving the blood-vessels. Dr. Simon's hypothesis/ 

 that such substances as urea, uric acid, and bilin, may be products of 

 active changes in the blood-corpuscles, has not been verified. 



(cxvui*.) TABLES of the Sizes of the Corpuscles of Blood, Lymph, 



Chyle, and Pus, in Vertebrate Animals. 



All the following measurements were made by myself. They are 

 compiled from papers published elsewhere, 5 containing more details as 

 to the names of the animals, the various sizes of the corpuscles, and 

 other particulars, than can be given here. Such additions and cor- 

 rections as further examinations have enabled me to make are now 

 introduced. The corpuscles of adult animals only are measured, unless 

 when mention is made to the contrary. The average diameter of 

 the corpuscles of each species is exclusively given ; in the blood of any 

 one of them, there are red corpuscles about a third smaller and a third 

 larger than the mean size ; and .among the pale globules of the blood, 

 chyle, lymph, and fluid of the thymus, still wider variations sometimes 

 occur. If the red corpuscles be obtained with difficulty from a minute 

 prick, they may be smaller, and more irregular in shape, than in blood 

 flowing freely from a larger wound. When the red corpuscles of 

 mammals are rapidly spread very thin and instantly dried on glass, they 



a Animal Chemistry, tr. for the Syd. Society, i, 160, 163, 219, 8vo, Lond. 1845. 



b On the Blood-Corpuscles of Marsupiata, of the Camelidce, and ofMoschusJavanicus, 

 Annals Natural Hist. Dec. 1839, Phil. Mag. same date, and Dublin Med. Press, Nov. 27, 

 1839; on the Blood-Corpuscles of Mammalia, Lond. .and Edin. Phil. Mag. for Jan. 

 Feb. March, and Aug. 1840 ; on the Blood-Corpuscles of Mammalia and Aves, in an 

 Appendix to the English version of Gerber's Anatomy, 8vo, Lond. 1842 ; on the 

 Nuclei of the Blood-Corpuscles of Vertebrata, Note to Dr. Willis's tr. of Wagner's 

 Physiology, pp. 240 et seq. 8vo, Lond. 1844, and Lond. and Edin. Phil. Mag. Aug. 

 1842 ; on the Pus-like Globules of the Blood, Phil. Mag. Sept. 1842, Note to 

 Wagner's Physiology (on the pale corpuscles of blood, lymph, and pus), pp. 250-52, and 

 Lond. Med. Gazette, Nov. 1, 1839; on the Blood-Corpuscles of the Camelida> and of 

 the MuskDeer, Med. Chir. Trans, vol. xxiii, and Lancet, vol. ii, 1840-41 , p. 101 ; on the 

 Blood-Corpuscles of the Snowy Owl and Passenger Pigeon, Proc. Zool. Soc. June 9, 

 1840; Corpuscles of Crocodilida, ibid. Nov. 10, 1840; Corpuscles of Paradoxures, 

 ibid.Nov. 24,1840; Corpuscles of Fme, ibid. May 25, 1841 ; Corpuscles of Marsupials, 

 ibid. June 8, 1841 ; Corpuscles of the Ibex and of Ophidian Reptiles, ibid. Aug. 9, 

 1842 ; Corpuscles of Strut hionidee, ibid. Oct. 11, 1842 ; Additional Measurements of 

 Blood-Corpuscles, ibid. Dec. 13, 1842, Feb. 13, and Sept. 10, 1844 ; Corpuscles of 

 the Stanley Musk Deer, ibid. May 9, 1843; Corpuscles of the Sloth, ibid. June 11, 

 1844 ; on the Lymph-Globules of Birds, Phil. Mag. June 1842 ; on the Structure of 

 Fibrinous Exudations, ibid. Oct. 1842 ; on the Lymph-Globules of Birds and Mam- 

 malia, Note to Wagner's Physiology, pp. 251-2 ; on the Size of the Blood-Corpuscles 

 of Vertebrata, Proc. Zool. Soc. Oct. 14, 1845 ; on the Size of the Blood-Corpuscles of 

 Birds, ibid. March 24, 1846. 



