238 HOMOLOGICAL RELATIONS OF THE 



The second and following intermediate forms (meta-scolex) 

 are represented 



In Mosses, by the spores, and filaments of the pro- 



tonema into which they germinate. 

 In Trematoda, by the second and subsequent gre- 



gariuiform zooids. 

 In Cestoidea, by the secondary and subsequent 



vesicles of the EcMnococcus. 

 But in the majority of Plants and Animals, not at 



all. 



ORTHOMORPHIC STAGE. 



The rudimentary condition of the typical form is re- 

 presented in plants and animals generally by the embryo. 



In Fungi, by the confervoid filaments of the nascent 



mycelium. 



In Lichens, by those of the hypothallus. 

 In Echinodermata, by the " disc." 

 In Ascidium, by the Spinula. 

 In Distoma, by the Cercaria. 

 In Insects, by the " maggot" or " caterpillar." 

 In Batrachia, by the " tadpole." 



When naked, the embryo is termed a larva ; when ex- 

 truded from the body of the parent, but still invested with 

 its own envelopes, it is termed a seed or egg. 



Secondary and subsequent phytoids or zooids, more or 

 less of the typical form, are represented 



In Vegetables, by the successive puljulations of ad- 

 herent leaf-shoots, making up the ramose vege- 

 tation of the majority of plants. 

 In the Polypifera and Polyzoa, by the successive 

 polypes, which, with their connecting stalks, 

 form the polypidom. 

 In Annelida, by the " joints" of the body. 



