16 J. BRONTK GATENBY 



(e) Changes in (1 h r o m o p h i 1 i t y during Oogenesis. 



Method I . — Fixation in saturated sohition of corrosive 

 subhmate, staining in Rhrhch's haematoxyhn and eosin accord- 

 ing to Scott's directions (55). The nucleohis of the oogonium is 

 amphophil with distinct ])a.S()pliilprepon{h'rance, i. e. more hhie 

 tlian rcnhhsh purple. The chromatinic reticuKim becomes oxypliil 

 after a c(*rtain time, and remains so throughout oogenesis ; 

 the oogonial cytoi)lasm is oxyphih During oogenesis at the 

 period of the appearance of the peri-nuclear bodies (nucleoli, 

 PI. 3, fig. 23) the cytoplasm becomes l)asophil, especially near 

 the nucleus. This basophility persists in a peri-nuclear position 

 for a considerable time and spreads out, l)ut gradually the 

 entire cytoplasm again becomes completely oxyphil. 



A typical somatic cell (e.g. gut, or epidermal) shows an 

 oxyphil cytoplasm and basophil nucleus. The head of the 

 sperm is basophil, the tail oxyphil. 



Method II. — The same material stained by eosin and 

 toluidin blue (in this order) offered a new point of view. 

 Somatic nuclei were blue, the sperm-head and most of the 

 epidermis cytoplasm blue also. The body-muscles and the tail 

 of the sperms were red. The oocyte cytoplasm had an oxyphil 

 ground, but the nucleolar deutoplasm was bluish. The nucleolus 

 itself was generally amphophil, and, as in the case of the 

 Ehrhch preparation, had a basophil central core and an ampho- 

 phil cortex with basophil preponderance. In other cases the 

 nucleolus was entirely oxyphil. The peri-nuclear bodies were 

 completely blue. 



While these results are in themselves of httle importance 

 from the point of view of the detection of peri-nuclear 

 ' chromatin omissions ', they show very clearly that at the time 

 when the primary oxyphilia is changing to the basophilia there 

 is great new activity in the region of the nucleus ; this activity 

 leads to the formation of new denser cytoplasm, and it will be 

 noted below that there is a correspondence between the pictures 

 given by methods explained above and with formalin silver- 

 nitrate or chrome-osmium techniques. 



