266 J. B. GATENBY AND J. H. WOODGER 
1. [yrRopuction. 
Ir is well known from the work of Retzius that the middle- 
piece of the ripe spermatozoa of many mammals bears around 
itself a small clear bead of protoplasmic material which can 
be easily recognized in the fresh sperm. 
In 1912 Weigl (82) published some comparative studies 
on the Golgi apparatus of the somatic- and germ-cells of 
different animals, in which he showed that the protoplasmic 
bead on the middle-piece of the spermatozoon of the guinea- 
pig contained structures possessing all the microchemical 
characteristics of true Golgi elements. 
The work out of which the present paper arose was primarily 
undertaken with a view to discovering the mode of origin of 
these argentophile structures from the Golgi apparatus of the 
spermatid and spermatocyte. 
The first part of this paper consists, therefore, of a description 
of our results in this field. 
The study of the Golgi apparatus of the spermatocytes and 
spermatid naturally led, however, to the investigation of the 
relations of this structure to other cell constituents, especially 
to the acrosome. 
The development of the acrosome in Cavia has been the 
object of repeated study by Niessing, Moore, Meves, and others, 
and quite recently by Papanicolaou and Stockard, but the 
exact relation of this body to the Golgi apparatus has not 
hitherto been described. 
Our observations upon this point form the second part of 
the present paper, and we have also attempted to give a general 
account of the spermatogenesis of Cavia based upon the 
confirmed results of modern workers, together with certain 
suggestions for a revised and simplified English nomenclature 
of the subject. 
9. Part I. The Development of the Definitive 
Middle-piece Golgi Apparatus. 
Retzius, as is well known, has published a large number of 
drawings of various mammalian and other spermatozoa. If 
