ITS DIFFERENT PHASES OF DEVELOPMENT IN THE ANIMAL SERIES. 
83 
stage coloration in a pretty marked degree, and that some are of an oval shape, 
give additional exactness to the comparison*. 
* In the descriptions -which have been given by authors of the corpuscles of the lymph much confusion exists. 
An exposure of the principal causes of this may perhaps prove useful and instructive. 
1st. Observations made on the corpuscles of the lymph of oviparous vertebrate animals have been adopted as 
applicable to the corpuscles of the lymph of Man and the Mammifera, whereas it will have been seen from what 
has been above said, that the corpuscles of the lymph of the oviparous Yertebrata can no more be taken as an 
exemplification of the corpuscles of the lymph of Man and the Mammifera, than the blood- corpuscles of the 
former as an exemplification of those of the latter. 
2nd. Hewson, it is known, gave the name of “central particles” to the nuclei of the red corpuscles of the 
blood of the oviparous Vertebrata. He at the same time supposed that he had seen similar particles in the in- 
terior of the red corpuscles of the blood of Man and the Mammifera. 
Having observed in the juice of lymphatic glands, bodies which he supposed to be free, and which he recog- 
nised to be similar to the central particles of the red corpuscles of the blood, Hewson came to the conclusion 
that the central particles are at first free, and that they subsequently become surrounded with the red coloured 
cell- wall, which he called “vesicular portion 1 .” 
How Hewson should have come to this conclusion is explicable, as regards the juice of the lymphatic glands 
of Birds, on the following supposition. In the juice of the lymphatic glands of Birds, it has been above seen, 
that nucleated cells in the uncoloured stage exist in great numbers ; but that whilst the nucleus is very di- 
stinct, the cell-wall is extremely pale. In consequence of this Hewson appears to have overlooked the cell- 
wall and distinguished the nucleus alone, but when the cell-wall had already become evident around the nu- 
cleus by having acquired colour, he naturally supposed that it was a new formation. 
How Hewson should have come to the same conclusion as regards the lymph of Man and the Mammifera, 
however, is scarcely explicable on any supposition. For to say nothing of the circumstance that there is not 
a “ central particle ” in the red corpuscle of the blood of the Mammifera, Hewson’s description of “ central 
particles ” in the juice of the lymphatic glands of the Mammifera cannot apply to the cellaeform nuclei of the 
uncoloured nucleated cells, seeing that the cellseform nucleus of the uncoloured nucleated cell is nearly, if not 
as large, as the perfect red corpuscle itself, which he alleged to contain the “ central particle.” The difficulty 
is still the same, even supposing Hewson to refer to free cellaeform nuclei in the uncoloured stage, and still 
greater supposing him to refer to granule-cells. 
3rd. Since Hewson’s time the cell-wall of the uncoloured nucleated cell in the lymph, especially of the ovi- 
parous Vertebrata. has continued to be generally overlooked, and the nucleus described as free. The nucleus 
moreover has been confounded with the granule-cell, which is what is commonly taken as the type of the 
“ lymph-corpuscle.” The same confusion prevails in regard to the lymph of Man and the Mammifera, with 
this. additional complication, viz. that granule-cells have been confounded with free cellaeform nuclei in the 
uncoloured stage. 
Wagner participating in the error of confounding granule-cells with cellseform nuclei, but having seen and 
distinguished the cell-wall of nucleated cells, he has taken their cellaeform nucleus for a granule-cell, which 
had acquired a cell-wall around it. 
Of all the authors I am acquainted with, Henle alone has accurately distinguished the different forms of the 
corpuscle of the lymph of Man and the Mammifera, without however pointing out their relationship ; but in 
his account of the corpuscles of the lymph of the Frog, he has fallen into inaccuracies similar to some of those 
which have been above pointed out. 
1 He believed, it may be further remarked, though not immediately to our present purpose, that the central 
particles were first formed in the lymphatic glands, and, after being received into the blood from the trunk of 
the lymphatic vessels, were in the course of the circulation carried to the spleen, where they acquired the red 
vesicular portion; and so the “red corpuscle” was formed. He believed also that the addition of the vesi- 
cular portion might likewise take place in the lymphatic glands. 
