140 J- Moore. 



bodies in the spermatocytes really represent the centrosomes. but both 

 at the period I have described and thi'oughout the subsequent phases 

 of division they ai-e quite outside the archoplasm originally present, 

 and never become related to it. nor are, the spindle fibres formed out 

 of this ai'choplasm. as I shall show. 



I have unfortunately not been able to extend these observations 

 with anything like the same degree of certainty to mammals other 

 than the rat; from what I have seen however, I am inclined to believe 

 that this exti'a-ai'choplasmic condition of the centrosomes obtains in 

 some and not in others. However this may be, it is seen that in the 

 spermatocytes the centrosomes need not be related to the archoplasm 

 of the cell, except when they occupy one of the apices of the spmdle 

 figiu'e. After the separation of the spermatocytes they lose connection 

 with the existing archoplasm. although this structure remains as one 

 of the most conspicuous featiu-es of the cell.. If we did not know the 

 mode of origin of the archoplasmic mass in these spermatocytes, the 

 non-inclusion of the centrosomes would furnish good groimd for doubting 

 the application of the term archoplasm to theii' Nebenkern, since in 

 this that structm-e differs from the archoplasm (sphere-attractive) of 

 those telles in the description of which, the term arose. We know 

 however that in Echiuoderms. Amphibians, and Pulmonates, the archo- 

 plasm is derived by a coalescence of the spindle fibres; and its general 

 relations to the centrosomes and spindle figiu'e in all these types 

 preclude any possibility of doubt that it is, in them, equivalent to the 

 structme originally described in Ascaris by the synonymous terms of 

 Archoplasm and attraction-sphere. Therefore. I think we cannot help 

 regarding the mass produced out of the spindle fibres of the mammalian 

 spermatocyte as also equivalent to the ai'choplasm: and we may amend 

 the expression, by terming it the archoplasmic portion of the attraction 

 sphere, reserving the latter term for the sum total of all the structui-es 

 ever included under that head. Accordingly, in the spermatogenesis 

 of the rat the sphere appears to be divided into two parts: one made 

 up of nothing but the residual spindle-fibres (archoplasm), and another 

 containing nothiup" but the centrosomes. Some such modification of 

 the cmrent terminology becomes almost necessary; because, from what 



