OF THE SPLEEN. 273 



colour, which is not the fact ; for the colour of the lymph in 

 any of the lymphatic vessels of the spleen, as nearly as we can 

 determine, is the same ; but that which is nearest the ligature, 

 to a careless observer, seems to be of a deeper red ; but this 

 appearance is occasioned only by the quantity being larger 

 from the increased size of the vessel. 



SECT. 76. These experiments were frequently repeated dur- 

 ing Mr. Hewson's lifetime, and many times since his decease, 

 and the appearances have been uniformly the same. 



SECT. 77. That the spleen is the organ ordained by nature 

 for the more perfectly forming these red particles we shall 

 endeavour to prove in the next chapter (cxxxin). 



(CXXXIIT.) Views more or less similar to Hewson's on the use of the 

 spleen, have been revived of late years by Tiedemann and Gmelin, 3 

 Schultz, b and Donne. c On the contrary, the second Dr. Monro d ob- 

 served that the spleen of some fishes which have but few red corpuscles 

 in the blood, is as dark and comparatively as large as in man ; and that 

 in a sturgeon six feet long, with blood abounding in red particles, though 

 he found seven spleens, the largest was not bigger than a dried horse- 

 bean. Professor M tiller 6 too objects, with reason, that the reddish colour 

 of the splenic lymph is not constant, and that the blood-corpuscles are 

 formed after the spleen has been extirpated. He also mentions that 

 in some fishes, myxine and the allied genus bdellostoma, the spleen is % 

 wanting ; and that its absence in the myxine had been noticed by feetzius. 

 It is curious that the blood of Mr. Yarrell's amphioxus lanceolatus/ 

 said to be the lowest of the fishes, has lately been observed by Retzius, 

 Miiller, and de Quatrefages, g to be perfectly colourless, destitute of the 

 ordinary red corpuscles, and only containing a few colourless ones, like 

 the blood of the invertebrata. 



Falconar rightly insists on Hewson's opinion, 11 that the spleen is not 

 the only organ capable of forming the red particles. Indeed, Hewson 

 removed it from a dog without any ill effect ; * and in the 'Philosophical 

 Transactions' for 1667, vol. ii, p. 521, there is an account, by Oldenburg, 

 of a bitch that had her spleen cut out, and afterwards took a dog and 

 bred puppies. 



a Recherches Experimentales sur la Di- e Physiology, tr. by Dr. Baly, vol. i, pp. 



gestion, tr. par Jourdan, torn, ii, 572, 567, 1st edit. 



p. 87, 8vo, Paris, 1827. f History of British Fishes, vol. ii, p. 468, 

 b Henle, Anatomie Generate, tr. par 8vo, Lond. 1836. 



Jourdan, torn, i, p. 511. . s Annales des* Sciences Naturelles, Oct. 



c Physiological Journal, No. 4, 8vo,Lond. 1845, p. 237, 3e Serie Zool. t. iv. 



j'an. 1844, p. 118. h See Sect. 82, 85, 88, 108. 



d The Structure and Physiology of Fishes ' Letter to Dr. Haygarth,p. 289 of this 



explained, p. 37, folio, Edin. 1785. volume. 



18 



