TRANSACTIONS OF SECTION K. 1069 



6. The Structure of the Yeast Plant. By Haeold Wager. 



1. The yeast cell possesses a spherical, deeply-stained body which has heen by 

 many observers regarded as a nucleus. This body is present in all cells except 

 young cells in process of formation, 



2. In close contact with this nuclear body is a vacuole which contains granules 

 and a network-like structure capable of staining in nuclear stains. The vacuole is 

 often surrounded by granules which stain in the same manner. 



3. These two — the nuclear body and the vacuole — are iu close contact with 

 one another, and in the process of division a portion of each passes into the 

 daughter cell. 



4. The granules of Hieromjmns occur, under the conditions described by him, 

 in large numbers ; and such cells are always found to contain granules which are 

 stainable in alkanin. It is very likely, therefore, that some or all of the granules 

 described by him are of an oily nature, although they do not easily dissolve in 

 ether. 



7. Observations on the Cytology o/Achlya Americana {Htimphrey) var. nov. 



By A. H. Trow. 



1. The nucleus in Achlya Americana has a structure which agrees in many 

 respects with that of the higher plants. Nuclei have been observed to undergo 

 indirect division in the oogonia and antheridia ; spirem monaster and diaster stages 

 have been observed. 



2. Most of the oogonial nuclei xmdergo degeneration, and the eggs even in the 

 earliest stages of their development are uni-nucleate. 



3. Fertilisation takes place as in Saprolegnia diclina and S. mi.ita ; the fer- 

 tilising tube possesses a single nucleus. 



4. The fusion of the gamete nuclei is generally delayed for two or three 

 days, but the fusion apparently always takes place a day or two before the oospore 

 becomes fully ripe. 



5. Fertilisation has thus been proved to take place in Saprolegnia diclina, 

 S. mixta, and in the variety of Achlya Americana which the author proposes to 

 call var. Cambrica, 



