62 



A flowerless plant is an associated colony of simple orga- 

 nized individuals (phytons) propagating by gemmation. 



A flowering plant, with stamens and pistils in the same 

 flower, is not a hermaphrodite individual; but is an or- 

 ganically associated colony of phytons, most of which are 

 simple and gemmiparous, but some through a higher 

 energy have been developed into distinct male and female 

 individuals. 



The so-called male of the Dioecious plants is an organi- 

 cally associated colony of gemmiparous phytons with true 

 male individuals ; and the so-called female plant is a similar 

 colony of gemmiparous phytons with true or perfect female 

 individuals. 



From plants to Aphides inclusive the phenomenon of 

 Parthenogenesis is presented under manifold modifications, 

 alike in this essential that they are all examples of organized 

 beings from the impregnated ovum of which many indivi- 

 duals may be successively developed. 



In the Vertebrated and in the higher Invertebrated ani- 

 mals only a single individual is propagated from each im- 

 pregnated ovum. Organized beings might be divided into 

 those in which the ovum is uniparous, and those in which 

 it is multiparous. This is the first and widest or most 

 general distinction which we have to consider in regard to 

 generation, and in proportion as we may recognize its 

 cause will be our insight into the true condition on which 

 Parthenogenesis depends. 



To this end we must revert to what takes place in the 

 impregnated seed or ovum at the beginning of develop- 

 ment, and duly ponder over the nature of the first steps in 

 embryonic formation. These, observation has now esta- 

 blished to be essentially the same in all organisms. The 

 spermatozoon has been traced to the ovum in the lower 

 Invertebrata and in Insects (where a special organ, the 

 spermatheca, exists to ensure its application), in Mollusks, 

 in Fishes, in Batrachians and up to the mammal. After 



