702 SPECIAL HISTOLOGY. 



diameter, completely corresponding with those mentioned as found in 

 the blood, and which are probably derived from the lymphatic glands. 



From the above facts, it would seem not to admit of doubt that the 

 lymph-corpuscles are formed, like cells, by the development of mem- 

 branes around free nuclei, a process which is effected, in the first place, 

 in the commencements of the lymphatic vessels, but also, and chiefly, 

 in the vasa efferentia of the lymphatic glands. To this is superadded 

 the multiplication of cells by division, which does not always take place. 

 The total quantity of the corpuscles, contained in the lymph, compared 

 with that of the blood-corpuscles, is very inconsiderable, not only in 

 the middle-sized and smaller trunks especially, of the lymphatics, but 

 even in the thoracic duct itself is very far from being in an equal pro- 

 portion ; and even there all the elements of the fluid may readily be 

 perceived, without any dilution. More precise enumerations have not 

 yet been instituted, and it can only be added that considerable diversi- 

 ties exist, and that a milk-white chyle is not always also rich in cor- 

 puscles.* 



* [Professor Kclliker appears not to be thoroughly acquainted with the very accurate and 

 extensive researches of Mr. Wharton Jones, embodied in his memoir on "The Blood-cor- 

 puscle, considered in its different phases of development in the Animal Series," "Philoso- 

 phical Transactions," 1S4G; the publication of which will, we believe, be considered here- 

 after to constitute an epoch in our knowledge of the blood. It is shown in this Memoir that 

 " the lymph-corpuscle of the Vertebrata is identical with the corpuscle of their blood. In 

 the oviparous Vertebrata it occurs, like the corpuscle of their blood, in the two phases of 

 granule-cell and nucleated cell ; whilst in man and Mammifera it occurs like the corpuscle 

 of their blood in the three phases, of granule-cell, nucleated cell, and free celloiform nucleus. 

 " The only difference that exists between the corpuscle of the lymph and the corpuscle in 

 the blood is, as regards the oviparous Vertebrata, the little degree of coloration which the 

 colored stage of the nucleated cell as yet presents, and, as regards the Mainmifera, the small 

 degree of coloration which the colored stage of the free celkeform nucleus has yet attained" 

 (p. 82). 



Mr. Wharton Jones first pointed out in this Memoir the true nature of the process which 

 is described and figured in the text as the "bursting," &c., of the lymph-corpuscles. These 

 changes of form, in fact, are not in general produced by any such cause, but they arise from 

 the amoeba-like motions of the corpuscles, observed by Mr. Jones in the Skate, Frog, and many 

 Invertebrata, and which may be readily enough seen on a smaller scale in the colorless cor- 

 puscle of the human blood. 



The subjoined description of the phenomena presented by the colorless corpuscle (granule- 

 cell, Jones) of the Skate will serve for all : 



" My attention was first attracted to the phenomenon, by observing a granule-cell with the 

 granules apparently escaping from it, as if burst (Fig. 3). But the cell soon appearing again 

 with all the granules collected together, I was led to watch, and soon perceived that the ap- 

 pearance of granules escaping as if from a burst cell, was owing to this : The transparent 

 and colorless cell-wall bulged out on one side, leaving the granules still agglomerated and 

 holding together, but this only for a short time ; for soon, single granules were seen to sepa- 

 rate and burst out from the rest, and to enter the hitherto empty compartment produced by 

 the bulging out of the cell-wall. The regular manner in which this sometimes took place 

 was remarkable. I have actually seen the granules enter the compartment by one side, 

 and circulate along the bulging cell-wall to the other side, until the whole compartment be- 

 came filled with granules. This having occurred, the bulging began to subside, but was 

 succeeded by the bulging of another part of the cell-wall, into which again a flow of gra- 

 nules took place, and so on all round the cell." 



