208 First Maturation Spinrllo of Allolobopliora Footida 



not vacuolated, contain small dark specks (see Photos. 5 and 14a) wliicli 

 can be clearly seen and ])hotograplied in unstained preparations, for they 

 are quite as black as the osmophile granules (see Photos. G8 and G9, 

 Plate lY, for these granules). They differ from osmophile granules, 

 however, in retaining their original color after staining with iron 

 ha^matoxylin. Photo. 14a shows them in an unstained, and Photo. 5 

 in a stained preparation, those of the latter were clearly seen and photo- 

 graphed l^efore the nucleolus was stained. In 1888 Vejdovsky figured 

 and described two nucleoli containing granules in the germinal vesicle 

 of Rhynchelmis (Taf III) and Montgomery in '98, figured dark granules 

 in several nucleoli, e. g., Figs. 267 to 269, but they cannot be the same as 

 those shown in our Photos. 5 and 14a, for Montgomery finds by change 

 of focus these dark granules can be transposed into small, clear vacuoles. 

 Photo. 14a demonstrates that this is not the case for Allolobopliora, in this 

 photograph some of the granules are out of focus, not all being on the 

 same plane, yet none of them appear as vacuoles. Photo. 14b is a nucleo- 

 lus from the same preparation as 14a and shows some of the vacuoles 

 quite as small as the black granules of 14a, but a change of focus on these 

 small vacuoles does not transpose them into granules. The granules 

 in 14a may represent an early stage of degeneration, a later stage being 

 shown in Photo. 75, Plate IV. 



The sixty photographs of nucleoli, shown in our plates, represent forms 

 figured by investigators for widely different material. These photo- 

 graphs show not only the varying forms of the so-called vacuoles, but 

 Photo. 4 shows a nucleolus sharply differentiated into the so-called chrom- 

 atic and achromatic portions, which can be differentially stained, and have 

 been described under a variety of names. Among later papers, such a dif- 

 ferentiation of the nucleolus has been demonstrated in Helix by Ancel, 

 '02, and in Teleosieans by Stephan, '02. Photos. 20, Plate I, 54, 55, 

 60, Plate III and 77, Plate IV, show the so-called nucleololus, or endo- 

 nucleolus, which Montgomer}^ and others pronounce an artefact. 



It is impossible to determine how many of the fantastic forms assumed 

 by the nucleolus of AUolohophora are artefacts, but the fact that definite 

 forms appear more or less constantly after certain fixatives creates a well- 

 founded suspicion of every form that cannot be verified by comparison 

 with the living egg. 



In AUolohophora there appears to be no fundamental difference be- 

 tween the principal nucleolus and the accessory nucleoli, and may not 

 the individualities of the former be due merely to its adaptation to 

 special needs of the egg during its growth period ? 



In many points the accessory nucleolus corresponds to the nucleoli of 



