Embryology. l 947 
development of the ovum (ovogenesis), or of the embryo itself 
_ (ontogenesis), since spermatogenesis and ovogenesis are processes 
_ which involve the maturation of the elements which enter the 
_ formation of the fertilized ovum or oosphere. All of these pro- 
cesses are therefore properly comprehended under ontogeny or 
= embryology in its widest sense. l 
= Dr. Benda’s carefully-elaborated memoir deals with the de- 
Cams, and Fels; the peculiarities in each case- are figured and 
_ discussed by the author, but the present writer must content 
s: 
T i The seminal tubuli of the mammalian testis. contain two 
4 kinds of histological elements, which are distinct in function, — 
a the Stammzellen, or spermospores, with their derivatives (mother- 
_ cells, spermatoblasts, etc.), and the “supporting cells” (H. H. 
K 
a Brown), or Fusszellen (Benda). 
2 Their functional activities are exhibited in four acts,—t. 
3 The multiplication of the Stammeellen (spermospores); 2. The 
_ Production of spermatoblasts from a part of the spermospores ; 
3 9pulation or union of the “ supporting cells,”’—Fusssellen 
=A . 
_ With a number of Spermatoblasts; and 4. The conversion of the 
 ‘permatoblasts, which have united with the supporting cell, into 
n Spermatozoa, ; 
Pi 
y 
3- These four processes take place successively and continu- 
sly (schübweise), 
4 The multiplication of the spermospores is effected by in- ` 
direct cell-divisip j ; i 
“€ seminal tubuli. 
Py ter the formation of a generation of spermatoblasts, each 
| functional « Supporting cells,” which lie next the outer- 
Most wall of the tubuli, conjugate with or become joined to a 
amet of Spermatoblasts. : 
mee Simultaneously or immediately after this conjugation has 
o Sstablished, the spermatoblasts are converted into sperma- 
