330 SPECIAL HISTOLOGY. 



the nuclei distinctly into view by rendering the contents clear, 

 of which occasionally a drop escapes from the ruptured cell ; at 

 the same time, at all events under the former reagent, the 

 nuclei not unfrequently are farther disintegrated, and fall into 

 irregular, jagged, and constricted corpuscles, or are even 

 resolved into a greater number, 4, 5, 6, and more, of smaller 

 granules, assuming at the same time a yellow colour, whilst 

 the cell-membranes gradually disappear. The other reactions 

 of these colourless blood-corpuscles are those of the common 

 indifferent cells, and as regards their number, it is, compared 

 with that of the blood-corpuscles, very small, though not always 

 the same, being dependent upon the energy with which nutri- 

 tion is going on, and therefore more considerable when a large 

 quantity of chyle has entered the blood after a full meal. It 

 is impossible to give any definitive statement as to their num- 

 ber, without perfectly accurate enumeration; but this much 

 is certain, that the usual statement, that there is one colourless 

 to every ten coloured blood-corpuscles, is quite incorrect. I find, 

 with Henle and Donders, that they are much less numerous than 

 this, and am of opinion, that when the latter, with Moleschott, 

 reckons 5*1 colourless to 2000 coloured corpuscles, he is not far 

 wrong. After meals, these authors found the number of the 

 latter augmented to 6*2, whilst in fasting animals, as was also 

 noticed by Heumann in Pigeons, they diminished in number; 

 and after long fasting, at least in Frogs, they saw them disap- 

 pear altogether. Their increase after venesections, not only 

 relatively but even absolutely, is a very remarkable circum- 

 stance ; and this, as in the Horse, after very copious abstraction 

 of blood (as much as 50 lbs.), may proceed to such an extent, 

 that the coloured and colourless corpuscles appear to exist in 

 equal numbers. The white corpuscles are lighter than the 

 coloured, and they are consequently more numerous in the 

 upper strata of the crass amentum. When the latter presents 

 a buffy coat, it always contains a great number of these cor- 

 puscles, and especially if their number has been augmented by 

 previous venesections, so as in such cases to constitute even 



Memoir above cited, should be consulted, as it contains the only complete account 

 of them extant. The statement in the text that Amphioxus has no blood-corpuscles, 

 is incorrect. It is, however, altogether exceptional among the Vertebrata, as its 

 corpuscles are entirely of the colourless kind.— Eds.] 



