THE SPERM. CENTROSOME AND ASTER OF ALLOLOBO- 
PHORA FOETIDA. 
BY ‘ 
KATHARINE FOOT anp E. C. STROBELL, 
Woods Holl, Mass. 
WiTH 1 PLATE. 
During the past few years evidence has accumulated which assigns to 
the egg attraction-sphere a position where it. threatens to usurp all the 
functions heretofore claimed for the male attraction-sphere. This pro- 
motion of the egg centrosome and aster with its satellites the cytasters, 
seems to have been at the expense of the male centrosome, until even 
Boveri can suggest as a possible hypothesis “‘Anstatt wie bisher zu sagen 
das Spermatozoon fiihrt ein Centrosoma ins Ei ein, miisste es heissen: 
das Spermatozoon bewirkt im Ei die Bildung eines Centrosoma, aus des- 
sen Teilung alle folgenden hervorgehen.” (Das Problem der Befruch- 
tung. Theodor Boveri, Jena, 1902.) 
The egg of Allolobophora furnishes evidence which indicates that the 
centrosome of its male attraction-sphere is part of the spermatozo6n itself, 
this evidence supporting the interpretation of Boveri and others, who 
maintain that the sperm centrosome is carried into the egg by the 
spermatozoon. 
In 1902* we demonstrated the constant presence of three granules 
in the spermatozoon of Allolobophora; one between the spine and head, 
one between the head and middle-piece, and one between the middle- 
piece and tail. Photographs of spermatozoa showing these granules can 
be seen in the above-mentioned article. 
It has been our aim to determine whether either granule at each end 
of the middle-piece forms the morphological center of the male attrac- 
tion-sphere, or whether the entire middle-piece must be regarded as the 
morphological centre. In every case in which we have found the middle- 
piece attached to the head, and its relation to the aster-rays could be 
therefore accurately demonstrated (photos. 1-8), it is certain that the 
‘The Spermatozoa of Allolobophora foetida. The American Journal of Anatomy, 
Vol. I, No. 3, 1902. 
