72 Proceedings of the Royal Irish Academy . 



Mallory's stain beiug his favourite method : he used as well two per cent, 

 osmie acid on fresh cells for twentj-four houi-s in order to study the 

 fat-content of the tissue. He mentions that he tried janus green, intra 

 vitam, for the mitochondria. 



In the corpus luteum of the sow, Corner has given a description of two 

 types of cells other than the luteal cells : these new types he calls additional 

 cells, type 1 and type 2. 



The American author finds a difficulty in saying whether additional cells, 

 type 2, represent a modification of the lutein cells or of the connective tissue. 

 He thinks that . there seem to be transitions in both directions. In one 

 recently ruptured follicle, the theca interna cells neai'est the granulosa were, 

 Comer shows, partly composed of cells similar in size, shape, and appearance 

 to the additional cells, type 2. 



In the cytoplasm of the sow's lutein cells. Corner recognizes an endoplasm 

 and an exoplasm. The latter is so full of granules and globules of diverse 

 substances that the nucleus of the fresh cell can sometimes hardly be seen. 

 Some of these granules are mitochondria, according to Corner. Other 

 globules are fatty and selectively stained by Suden III and osmie acid. 

 Corner goes on to discuss (and confuse!) the trophospongium of Holmgren, 

 and the inner network of Golgi, and compares certain empty spaces he finds 

 in the luteal cells of the sow, with the Golgi apparatus or the trophospongium. 

 In his figure 7, the canals shown probably have no connexion with the Golgi 

 apparatus : in figs. 5, 6, 9, 11, 13, and 15, Corner draws cells which, unknown 

 to him, show the position occupied by the Golgi apparatus. In a more recent 

 paper, however, he corrects some of his misinterpretations. 



Miller denies the presence of neutral fat in the human menstrual corpus 

 luteum. 



The various discrepancies between the accounts of these different 

 authors depend largely on mere nomenclatui-e : some workers call everything 

 that goes black in osmie acid, fat. Osmie acid blackens according to no very 

 definite rules, and without more extended experimentation it is impossible to 

 say whether or not neutral fat is present. 



Apparently in the sow, horse, cow, and cat, the cells of the corpus luteum 

 do contain a substance which blackens in osmie and Sudan III, and these 

 globules are probably, but not certainly, neutral fat. The presence of neuti-al 

 fat in the gland cells of the coi-pus luteum is paralleled by the presence of fat 

 in the cortical substance of the supra-renal. 



Mnier in 19 1-1 stated that the corpus luteum of human pregnancy diffei-s 

 from that of menstruation or ovulation, in that the former gives no neutral 

 fat-reaction and exhibits no colloid degenerative changes. From an 



