256 GREGOR T. POPA. 



to say, the tip of the head) of a minute opening, which it is 

 convenient to call by analogy micropyle; and also at the con- 

 necting region there is another small ring very easily colored by 

 stains which have affinity for chromatin, especially by carbol- 

 pyronine. This is the classical proximal centriole. 1 



We have seen above the various changes of the mutual relations 

 of the two substances in the head of spermatozoon. The end 

 result of these changes is the elimination of the lateral body. 

 This elimination phenomenon occurs, also, under various other 

 circumstances, for instance, when spermatozoa are in weak 

 formaldehyde solution, or in some staining solutions, but the 

 process takes place very slowly and quite irregularly. On the 

 other hand, in the egg-water after five minutes almost all sperma- 

 tozoa show this lateral body. 



Fresh preparations of spermatozoa of Arbacia in egg- water 

 also show quite clearly the elimination of a substance through 

 the pointed apex of the spermatozoon. This appears as a small 

 granule on the points of almost all spermatozoa. The adhesion 

 of the spermatozoa to one another or to other objects is made by 

 means of this granule. 2 In the middle of some clusters one can see 

 groups of such granules very refractile, round and close together. 

 For this observation only fresh preparations are to be trusted, 

 because stains may form very fine precipitates which cannot be 

 distinguished from drops of the eliminated substance. 



Very probably, under the influence of some chemical sub- 

 stances included in the egg- water (Lillie's fertilizin?) spermatozoa 

 eliminate through the micropyle a sticky substance, which so 

 long as it still adheres to the apex of spermatozoa keeps them 

 agglutinated. After it is lost from the tip, the spermatozoa 

 spread out again in the fluid. I cannot decide if this substance 

 exists as such in the spermatozoon or if it is produced by a 

 secretory process at the moment of stimulation by egg-water, 

 as in the sense of Bowen. 3 



1 Here also is the opening observed by Mischer and Ballowitz (loc. cit.) and 

 called by the former worker microporus. 



2 Ballowitz, E. (Zeitschr. f. wiss. Zool., 1890, Bd. 50, S. 317) called this granule 

 "Spitzenknopf " and noticed its instability (p. 375). 



3 According to R. H. Bowen, who adopts the theory of Nassonov concerning the 

 role of Golgi apparatus, "Das Golgische Binnennetz und seine Beziehungen zu 

 der Sekretion. Untersuchungen iiber einige Amphibiendrusen," Arch. f. mikr. 

 Anal., 97 Bd., 136, the acrosome should be a secretory organ and the granule on 



