652 EISEN. [Vol. XV. 



B. THE BLOOD-CORPUSCLES OF AMPHIUMA AND NECTURUS. 



XI. General Remarks on the Erythrocytes. 



In the following pages I will confine myself to a description 

 of the structure of the red corpuscles and to their derivatives, 

 the fusiform corpuscles. I expect to show that in the blood of 

 the above-named batrachians we must distinguish between two 

 different kinds of red blood-corpuscles, differing from each other 

 in size, form, and structure. In one class (PI. XXXVI, Figs. 

 22, 23) we find groups of centrosomes suspended free at the poles 

 of the cell, far away from the nucleus ; while in the other class 

 (PI. XXXVI, Fig. 24) we find no such groups, but, on the con- 

 trary, an archoplasmal structure with centrosomes, situated in a 

 granosphere close to the nucleus. Corresponding to the two 

 classes of red corpuscles we find two classes of fusiform cor- 

 puscles derived from the former. In one class the centrosomes 

 are seen to be free and far away from the nucleus (PI. XXXVI, 

 Fig. 25) ; while in the other the archoplasmal structures lie in 

 a depression of the nucleus, one at each pole. The structure 

 of the centrosomes will be described in detail ; and as regards 

 their nature and function in the first-mentioned class of cor- 

 puscles, it may be suggested that their function is purely 

 mechanical, for the purpose of balancing and guiding the 

 large oblong cells through the capillaries, thus preventing 

 stagnation and undue obstruction. 



XII. Two Kinds of Erythrocytes and Two Kinds of 

 Fusiform Corpuscles. 



Not only in the blood of AmpJiiiima and Necturus, but in all 

 other batrachian and reptilian blood examined by me, have 

 been found two distinct kinds of nucleated erythrocytes. One 

 is more round than the other, and the two kinds stain some- 

 what differently. In Amphiiima and Necturus erythrocytes of 

 the oblong kind described above possess directing globules, 

 while the rounder kind have none. The nucleus of the former 

 is longer and narrower, with an uneven outline ; that of the 



