PARTS CONCERNED IN REPRODUCTION 239 



In Insects, by the " viviparous Aphides' and other 



like forms. 



The ultimate phase of the typical stage is represented 

 In Fungi, by the fruit-bearing plant. 

 In other lower Cryptogamia, by the thallus. 

 In Mosses, by the perichaetial leaves. 

 In Ferns, Equisetacese, Lycopodiacese, &c., by the 



sporangium. 



In the higher plants, by the floral organs. 

 In the Polypifera, by the " urn" (gonophore) and 



blastostyle. 



In the Trematoda, by the Distoma-form. 

 In the Cestoidea, by the mature Tsenia-head. 

 In Insects, by the Imago, generally winged. 

 In Animals generally, by what is recognised as the 



adult form* 



GAMOMORPHIC STAGE. 



The proper sperm or germ stock (strobila, proglottis) is 

 represented 



In Algae, by the androspore of Bulbochwte. 



In Fungi, by the hymenium. 



In Lichens, by the apothecium. 



In Mosses, scarcely at all. 



In the higher Cryptogamia by the spore, and the 



prothallium developed from it. 

 In the Phanerogamia, by the pollen grain and ovule. 

 In the Polypifera, by the medusoid, or the sporosac. 

 In the Cestoidea, by a proglottis, or cucurbitiform 



segment, as in Tcenia. 



* In the higher Animals, however, as will be presently noticed, the 

 adult state represents, in addition to the typical form, the rudiments 

 also of the gamomorphic, in the parts of sex, implanted at a compara- 

 tively early period of embryonic development, on the pre-existing struc- 

 ture known as the Wolffian body. 



