ITS PHYSICAL, CHEMICAL, AND STRUCTURAL CHARACTERS. 169 



Lastly, the correspondence pointed out by Mr. Wharton Jones (loc. cit.), be- 

 tween the successive phases presented by the Blood-corpuscles in the animal 

 series, and those through which, according to the views above stated, the Red 

 corpuscle passes in attaining its complete form in the highest animal, is really 

 extremely close. For in the blood of the Invertebrata, as in the chyle and 

 lymph, and occasionally in the blood of Yertebrata, are found " coarse granule- 

 cells," which seem to be in the first stage of development, and "fine granule-cells/' 

 which may be regarded as in the second. This leads on to the " colorless nucle- 

 ated cell/' which is the highest form presented by the corpuscles in Invertebrated 

 animals, but is, as we have seen, a mere transitional stage of brief duration in 

 those of Vertebrata. The "colored nucleated cell," again, is the highest form 

 of red corpuscle in the Oviparous Vertebrata ; and this corresponds with a 

 more advanced stage of development in the red corpuscle of Mammalia. The 

 " colored non-nucleated cells" of the latter are to be regarded as exhibiting that 

 highest phase of development, in which the nucleus disappears, apparently in 

 virtue of the completion of its formative office, and of its resolution into the 

 fluid contents of the cell. 



151. Notwithstanding the strength of the foregoing evidence, yet there are 

 certain considerations which render it difficult to give an unreserved adhesion to 

 this doctrine of the transformation of the chyle- and lymph-corpuscles into the 

 red corpuscles of the blood, through the intermediate grade of the white. For 

 although the correspondence in size between the lymph-globule, the colorless 

 blood-corpuscle, and the red corpuscle, is so close in Man as to sanction this idea 

 of their relationship, yet no such correspondence exists elsewhere ; for we find 

 that, as the diameter of the lymph-globules and of the white blood-corpuscles 

 remains pretty constant, whilst that of the red presents a wide range of variation 

 in different animals, there comes to be a strongly-marked disproportion between 

 them; the lymph-globules of the Musk-deer, for example, being of the usual 

 size, whilst the diameter of the red corpuscles is less than 1-12, 000th of an inch, 

 or no more than a quarter of the preceding; the lymph-globules of oviparous 

 Vertebrata being usually of no larger diameter than the nuclei of their red cor- 

 puscles, and where (as in the Perennibranchiate Batrachia) the red corpuscles 

 are of enormous size, having even a far less diameter than their nuclei. The 

 form of the lymph-globules and of the colorless corpuscles, moreover, is always 

 circular; yet that of the red corpuscles and of their nuclei is oval in all the 

 oviparous Vertebrata, the ratio between the long and the short diameters of the 

 corpuscles being frequently as 2:1, and between the diameters of the nuclei 

 being sometimes as 3.3 : 1. Hence until it shall have been shown how these 

 differences are obliterated in the course of the developmental process how the 

 lymph-globule of the Musk-deer either contracts or subdivides, so as to form a 

 blood-corpuscle of one-sixteenth of its area and how the round lymph-globule 

 of the Proteus swells out into an oval cell of thirty or forty times its dimensions, 

 the proof must be considered as far from complete. And even if it be admitted 

 that the red corpuscle is originally developed from the lymph-globule, and that 

 this is also the source of the colorless corpuscle, still it would seem quite possible, 

 that the Red and the Colorless corpuscles are to be regarded as two distinct and 

 complete forms, neither being capable of metamorphosis into the other, and each 

 having a specific purpose to serve in the economy. For, so far as can be judged 

 by appearances, there is a close correspondence between the Colorless corpuscles 

 and the corpuscles of those " Vascular Glands" which are developed in connection 

 with the Absorbent and Sanguiferous systems, and which seem to have it for 

 their office to assist in elaborating the nutrient materials of the blood (CHAP. 

 VIII. SECT. 3). And there are many indications, as will hereafter appear, that 

 their function is not dissimilar; whilst, on the other hand, there is no corre- 



