COURTSHIP 183 



change in the surrounding conditions of life as the new 

 blend may be. Thus a more certain and active pro- 

 duction of possibly useful variations is provided for 

 than would be the case were the variations of one self- 

 multiplying stock alone presented for selection. 



In the case of simple conjugation the cell individuals 

 which fuse or " mate " with one another, and may be 

 called " maters " or " mating cells," are in all respects 

 similar to one another. But we find among the uni- 

 cellular plants and animals cases in which one of the 

 mating cells, instead of fusing with another straight away, 

 divides into a number of much smaller cells, which are 

 very active in locomotion and are specially produced in 

 order to mate or fuse with the larger cells. The mating 

 cells are called " gametes," and the large motionless 

 mating cells are called " macro - gametes," or " large 

 maters," whilst the small motile mating cells are called 

 " micro-gametes," or small " maters." The former are of 

 the same nature as egg cells or ovules, the female re- 

 productive particles, whilst the latter, the small " maters," 

 are identical in nature with the sperms or spermatozoa 

 or male reproductive particles of higher organisms. In 

 the case of certain parasitic unicellular .animals called 

 coccidia, and also in the parasite which causes malarial 

 fever, quantities of small " mating cells " are produced 

 which fuse with or " fertilize " other much larger mating 

 cells. The small " maters " of coccidia have long 

 vibrating tails and minute oblong bodies, and agree 

 closely in appearance and active locomotion with the 

 spermatozoa of higher animals and plants. The large 

 spherical mating cells might be mistaken for the egg 

 cells of larger animals. In the globe animalcule, Volvox 

 globator, we find a transitional condition leading us 

 to the production of small (male) and large (female) 



