INVETITEBKATA, CRYPTOGAMIA, MICROSCOPY, ETC. 699 



the author states that he has observed a faint striation, and the regular 

 arrangement of isotropic and anisotropic substances. 



With regard to the ovarian follicle, we shall only observe that the 

 abortion of the ovum is connected with the following phenomena : — • 

 The germinal spot disappears, and its place is taken by a small 

 collection of angular and glistening waste products, or by a radially 

 striated sphere formed of crystalline carbonates ; the same fate awaits 

 the gei-minal vesicle, and the whole of the yolk, but the zona jjellucida 

 may remain. 



Corpus lateum. — The author, in examining a bitch, twenty-four 

 hours after impregnation, found three large follicles in one ovary ; 

 from these, when opened, there escaped a small sphere of gelatinous 

 matter, in which two ova were found. The walls of the f(jllicle were 

 seen to be very richly provided with vessels, and were thick ; fourteen 

 days after impregnation the vessels were found to be greatly increased 

 in number and in size, and after twenty-one days the corpus luteum 

 was found to be com2)]etely developed, and a number of " giant cells " 

 were found in close proximity to the vessels ; these accompany the 

 vessels and gradually surround the cells of the corpus luteum, giving 

 rise in time to fibrillaB, which convert the body into a corpus albicans 

 or nigricans ; they are, in fact, the rudiments of the fibrillaa of the 

 connective tissue, and as they increase the cells of the yellow body 

 undergo atropliy. Changes now occur in the contents of the blood- 

 vessels which give rise to rusty brown aggregations, and the blood- 

 vessels themselves die down. The surrounding tissues also suffer, 

 and the wall of the follicle ceases to be apparent, while a whitish spot 

 is at last all that is left to tell the tale of the changes that have taken 

 place. 



Natural Science Prizes, Banish Academy.— -{Before 31st October, 

 1880. English allowed.) — (1) A series of comparative researches 

 on the formation and development of the embryo sac and of the 

 cells which it encloses before fecundation, made on a sufficiently 

 large number of ditFerent angiosperms, so as to really increase the 

 extent of our knowledge, bearing either on the law of development 

 itself or on the general systematic importance of the differences 

 which are presented, and to enable us at the same time to establish 

 on a more solid basis than formerly the morphological value of the 

 parts of the ovule.* (Gold medal of the Academy, value 320 crowns.) 



2. Recent researches seeming to make it doubtful whether the salts 

 of soda, so widely spread in the soil and in vegetable ashes, are really 

 as necessary to the normal development of plants as the salts of potash, 

 lime, magnesia, and iron, a research is required, which shall solve 

 this question in regard to any wild and cultivated plants of Denmark."]" 

 (Thott prize, value 400 crowns.) 



3. Original researches and experiments, which shall contribute to 

 the elucidation of the development of the Disioma of the sheep, and 

 that of their migrations until they arrive at the liver, as well as the 



* Cf. ' Over&igt Danske Videnak. Sclsk. Forhand.' (1879) p. 2S. ('Resume du 

 Bulletin,' p. 5.) t IWtl-, p. «• 



