112 LIVERPOOL BIOLOGICAL SOCIETY. 
that physiological equivalence is not sufficient to over- 
balance the great morphological differences implied in the 
origin and mode of formation of the so-called sexually- 
produced spore. Moreover, even looked at physiologically, 
the very fact that sexual reproduction does occur, and that 
too at critical periods in the life of many forms, and that 
the spore produces sooner or later a gamophyte, while the 
fertilized ovum produces a sporophyte, surely points to 
the supreme importance of the sexual origin of embryos, 
and the fundamental difference between such a product 
and aspore. It is to the organs of reproduction in plants 
that we must go in the first instance for a clue to their 
genetic relationships. In the animal world, one might 
almost say, the evolution has been an evolution of organs 
connected with the maintenance of individual life, whilst 
in the plant world the evolution has been one of the organs 
connected with the maintenance of tribal life. We may 
perhaps look on this fact as affording some clue to the 
relatively higher organisation of the animal, and its con- 
tinued individual evolution accompanied by the marked 
decrease in its reproductive powers. The plant on the 
other hand shows comparatively low individual organisa- 
tion, but vast powers of multiplying its kind. For these 
reasons alone I would be disinclined to accept Vines’s use 
of the term ‘‘spore.”” The obvious confusion which must 
necessarily arise from the application of the same term to 
two products so different in their origin and morphological 
and physiological value in itself forms no slight objection to 
this terminology. By a spore then I would indicate the 
physiologically perfect cell which may be separated from 
a plant, and which, without union with any other cell, 
may become under suitable conditions an adult organism. 
Naturally this exclusive use of the word spore would form 
