SPERMATOGENESIS IN THE ALBINO RAT 171 



one, a body which I have identified as a tardy chromosome — 

 usually chromosome A. 



Duesberg agrees with me that the idiosome is not found in the 

 spermatogonia, but makes its appearance in the early stages of 

 spermatocyte growth. He does not describe its division, but 

 shows the centrosomes within it. He agrees with Lenhossek 

 that it disappears without dividing in each of the spermatocyte 

 divisions, but differs from him in stating that its staining reaction 

 weakens as the cell prepares for division. • In the spermatids he 

 decides that a part helps in the formation of the acrosome and 

 the other part is lost in the cytoplasm which is eliminated. 



Von Winiwarter ('12) notes it first in the growth stages of the 

 first spermatocytes, but in this respect he states that he differs 

 from both Branca and Montgomery (man) and Schoenfeld ('01) 

 (bull). As to the division of the idiosome, he states that ''it 

 disappears and perhaps degenerates" when the first spermatocyte 

 divides. He does not mention it, nor do his figures show it in 

 the later stages. He states that the central corpuscles remain 

 within the idiosome until the pre-equatorial plate is formed, when 

 they emerge and separate to form the spindle. Montgomery 

 ('12) (man) states that he finds ''no trace of a sphere in sperma- 

 tocytes nor spermatids." 



The chromatoid body was also early noted. Lenhossek ('98) 

 treats it at length, and identifies it with the large characteristic 

 body in the cytoplasm of the spermatid to which I have j^ef erred 

 (p. 155) and figured (fig. 1). He thinks its fate is to take part in a 

 temporary structure connected with the spermatozoon head. 

 Montgomery ('12) does not mention it nor figure it. Von 

 Winiwarter ('12) does not find its exact equivalent, but notes 

 "a certain number of chromatophiles " which may conjugate into 

 "a sort of little rod." These chromatophilic corpuscles occur in 

 more or less abundance during all the stages of maturation, he 

 states, and notes a 'chromatoid body' in the spermatids in addi- 

 tion to the chromatophile corpuscles. 



Duesberg ('08) (rat) identifies the large heavily staining body 

 in the cytoplasm of the spermatids as the chromatoid body, 

 traces it briefly in connection with the centrioles (without stating 



