254 GREGOR T. POPA. 



there are two colored strips and one light band; (d) The same 

 process, much more advanced; (e) The lipochromatic substance 

 accumulated in greater amount, shifts from the connecting 

 region; (/) A round or slightly oval body is thus extruded 

 from the head, and it takes a lateral position, where it persists 

 without any modification, and the whole spermatozoon becomes 

 perfectly quiet. It is to be noticed that the spermatozoa which 

 have extruded this lateral body do not swell. On the other hand, 

 the spermatozoa which have not extruded it, swell and become 



round. 



III. DISCUSSION. 



Summarizing all the facts revealed by the various methods 

 above described, concerning the topographical distribution of the 

 material in the spermatozoon (in Nereis and Arbacia) there is to 

 be distinguished a substance stained by lipophilic stains, the 

 lipochromatic substance; and another substance very avid for 

 water, the hydrophilic substance. The lipochromatic substance is 

 located at the periphery of the spermatozoon, and its thickness is 

 variable in different regions; towards the connecting region it 

 constructs a large ring and the sensillae; in the tail it takes part 

 in the construction of the tail mantle. This substance is not 

 avid for water, and therefore does not change its volume in 

 various hypotonic solutions. On the other hand, it shifts position 

 readily, and it accumulates normally in the connecting region of 

 the spermatozoon (Fig. u). 



The hydrophilic substance is located in the axis of the sperma- 

 tozoon, and does not take the lipophilic stains. In the head it 

 includes the nucleus or may be represented exclusively by the 

 nucleus. It is extremely hydrophile, swells in water (hypotonic 

 solutions) and thus enlarges the head of spermatozoon until 

 more than three times diameter. This substance is centrally 

 located in the head and also in the axis of the tail. 1 



Apparently the hydrophilic substance of the head is nothing 

 else than the nucleus and the lipochromatic substance must be 



1 Concerning the sensitiveness of these cells to the changes in the osmotic pressure 

 see: Richard Goldschmidt, "Kleine Beobachtungen und Ideen zur Zellenlehre III 

 Die Bedeutung der atypischen Spermatozoen," Arch. j. Zellforsch., 14 Bd. F 1921, 

 S. 290. Richard Goldschmidt, "Versuche zur Spermatogenese in vitro," Arch. f. 

 Zellforsch., 14 Bd., 1921, S. 421. Josef Speck, " Neue Beitrage zum Problem der 

 Plasmastrukturen," Zeitschr. f. Zellen- u. Gewebelehre, I Bd., 1924, S. 278. 



