No. 2.] COMPARATIVE CYTOLOGICAL STUDIES. 359 



with it by linin fibers ; but he was unable to decide whether 

 these granules are thickenings of linin fibers, or whether they 

 correspond to " Nucleolen bezw. Nebennucleolen . . . , welche 

 sich vielleicht vom Mutterkorper getrennt haben und durch 

 Wirkung centraler Lebensherde in jener typischen, regel- 

 massigen Stellung verharren." 



vom Rath (-953) studied the maturation of the ovum of 

 Euchaeta viarina : on PI. VII he figures a number of various 

 sized, all rather large nucleoli, in the germinal vesicle, at the 

 stage when the chromosomes are longitudinally cleft. 



vom Rath ('95b) finds that the secretion of the gland cells 

 of the head in Anilocra stains exactly like the nucleoli, and 

 concludes that both substances are probably chemically related. 

 He briefly mentions (footnote, p. 5) having seen double nucleoli 

 in liver cells of molluscs and Aiuphibia ; these dumbbell- 

 shaped nucleoli may be either regarded as states of fusion or 

 of division. In liver cells of Astacns the nucleolus consists of 

 "zwei verschieden tingirten einander dicht anliegenden Kugeln 

 einer dunklen und einer blassen." There is no relation between 

 centrosomes and nucleolar substance. 



Rhumbler (-95) studied the nucleolar relations of Cyphoderia. 

 From three to nine «' Binnenkorper " lie within the nucleus, the 

 largest nuclei having the smallest number ; so that accompanying 

 the increase in size of the nucleus, a gradual fusion of the 

 "Binnenkorper" takes place, though without an appreciable 

 increase in the total volume of their substance. 



Sacharoff (-95) concludes that since the eosinophilic granules 

 of the blood have the same appearance as the nucleoli, " und 

 weil diese Kernkorperchen bei dem Herausfallen der Kerne auch 

 herausfallen miissen, um dann unweigerlich von Leukocyten 

 verschlungen zu werden, so ist mit grosster Wahrscheinlichkeit 

 anzunehmen, dass bei Saugern die eosinophilen Granulationen 

 auf dem Wege der Phagocytose von aus Hamatoblasten heraus- 

 gef.illenen Kernkorperchen entstehen." In birds the nuclei 

 do not fall out of the erythrocytes, but the eosinophilic cor- 

 puscles are nucleoli which have wandered out of the nucleus ; 

 these nucleoli are rod shaped. (Only medical literature is cited 

 in this paper.) 



