160 PRACTICAL BOTANY 



in either case the dry seed may be used : treat as the 

 above. Examine with a low power, and make out 



1. Calyptra (root-cap). 



2. Piliferous layer. 



3. Periblern. 



4. Plerome, forming the procambium and pith. 



But here all the different tissue-systems will be 

 found to originate from a general meristem, the original 

 formative tissue of none of them being distinct from 

 that of the others. This type may be expressed, 

 shortly, thus : 



Calyptrogem 



Dermatogen|All united in a general, undifferentiated 

 jPeriblem | mass of meristem. 

 [Plerome 



As alternative plants of the same type, may be 

 named Cucurbita and Pisum. 



