26 MORPHOLOGY OF ANGIOSPBRMS 



" ovary " also, as usually applied, has no definite morphological 

 significance, referring to a morphologically single sporangial 

 chamber or to a combination of several such units, and these 

 chambers may be of axial as well as of carpellary origin. The 

 various ways in which the congenital carpels are related to one 

 another in a compound pistil are of great service in taxonomy, 

 as the particular structure of such a pistil is usually charac- 

 teristic of great families, or even of groups of higher rank. 

 These details of structure are too fully presented in various 

 texts, however, to justify their repetition here. The relation 

 of sporangia to carpels is an important subject to the morpholo- 

 gist, and will be considered in connection with the development 

 of the sporangia. 



