340 PROCEEDINGS OF SECTION D. 



From this point of view the termination jjhyte is obviously in- 

 applicable, as well as the whole name sj^oropliyte, since what we 

 wish to express is the fact that the asexual generation multiplies 

 by budding ; the fact of the bud being in some cases unicellular 

 (spores), and in others multicellular (zooids) is of quite secondary 

 importance. I, therefore, venture to suggest blasfohium for the 

 asexual, and gamohium for the sexual generation : the former is 

 equally applicable to a fern-plant or a hydroid colony, the latter to 

 a prothallus or a medusa. 



The following table, giving a classification of the chief methods 

 of sexual reproduction, will serve to illustrate the applications of 

 the terms proposed, and to show how far they differ from those 

 ordinarily used, and from those proposed by Mr. Harvey Gibson. 



Sexual reproduction consists in the conjugation of two cells 

 {gametes), the essential part of the process being usually the 

 union of their nuclei. The following are the chief variations in 

 the process : — 



A. The union is temporary, accompanied (probably) by an 



exchange of nuclear material, and followed by increased 

 activity in fissive multiplication : gametes equal and similar, 

 and co-extensive with the conjugating organisms. 



Paramoechtm, Stylonychia, &c. 



B. The union is a permanent one, resulting in Ihe formation 



of a zygote, the nucleus of which is (? alM^ays) formed by 

 the fusion of the nuclei of the two gametes. 



I. The gametes are equal and similar. 



a. The gamete is co-extensive with the organism, the two 



unicellular sexual individuals undergoing total fusion. 

 a. The protoplasm of the zygote undergoes multiple fusion, 

 producing numerous Hagellullre or swarm spores. 



Reteromita, Dallingeria, &c. 



/3. The zygote is a %ygo::oos'pore, or free-swimming 

 flagellate cell. Protococcacecf^ 



b. The gamete is co-extensive with the cell-body of the 



organism, or is formed by its division into two : the 

 cell- wall or its outer layer takes no part in conjuga- 

 tion. In this case the entire cell may be looked upon 

 as a gonad. Zygote, a zygospore, which after a period 

 of rest gives rise to one or more individuals of the 

 ordinary kind. Desmids, some Diatoms. 



c. Gametes produced each from a single cell (gonad) of the 



organism, the greater part of which takes no part 

 in conjugation. Zygote, a zygosjyore, or resting cell. 



Mftcor, Mesocarpus, &c. 



