226 RAMBLES OF A NATURALIST. 



We may, however, instance a very remarkable 

 difference between animals and plants in respect 

 to the relations which we have been considering. 

 Among the former, the sexes may generally be 

 recognised throughout the whole of life, by ex- 

 ternal or internal characters. This is not tlie case 

 with plants. The male and the female date-tree 

 grow side by side, and exhibit no difference until 

 the moment when the appearance of the flowers 

 reveals their different characteristics. In the animal 

 kingdom, the Syllis presents us with a similar fact. 

 At ordinary times we find only individuals which 

 are in no w^ay distii guished from one another. But 

 no sooner has the season of reproduction arrived, 

 than like the palm-tree, which throws forth its 

 flower, the Annelid produces new parts, which are 

 added to the older organs, and which alone assume 

 the characters essential to the two sexes. Thus in 

 the case in point, the tree and the animal are alike 

 neuter up to a certain period. At a subsequent 

 epoch we find the tree manifesting its sex by the 

 appearance of flowers, the animal by the production 

 of a secondary individual, which may therefore be 

 regarded as a veritable animal flower, appearing on 

 the primary stock. 



Let us pursue this curious parallel, and see what 

 mode of production already observed in the vegetable 

 kingdom may be compared to that which we have 

 found to exist in several of the Medusidas. 



Every one is acquainted with the Agaricus cam- 

 pestris, that mushroom which is artificially propa- 

 gated to supply the great quantities which are 



