332 GLOSSARY 



INDUSIUM : in Ferns a flap-like membrane protecting a sorus. 143. 



INFLORESCENCE : a flower-cluster. 230. 



INSERTION : the point of origin of an organ. 224. 



INTEGUMENT : in Spermatophytes a membrane investing the nucellus. 



178. 

 INVOLUCRE : a cycle or rosette of bracts beneath a flower-cluster, as iu 



Umbellifers and Composites. ~7~>. 

 ISOCARPIC : applied to a flower whose carpels equal in number the other 



floral organs. 268. 

 ISOGAMOUS : applied to plants whose pairing gametes are similar. 15. 



LEPTOSPORANGIATE : applied to those Ferns whose sporangia develop 

 from a single epidermal cell. 157. 



MALE CELL : in Sperm atophytes the fertilizing cell conducted by the 



pollen-tube to the egg. 180. 



MEGASPORANGIUM : a sporangium which produces only megaspores. 152. 

 MEGASPORE : in heterosporous plants the large spore which produces a 



female gametophyte. 152. 

 MEGASPOROPHYLL : a sporophyll which produces only megasporangia. 



152. 

 MESOPHYLL : the tissue of a leaf between the two epidermal layers which 



usually contains chloroplasts. 141. 

 MICROSPORANGIUM : a sporangium which produces only microspores. 



152. 

 MICROSPORE : in heterosporous plants the small spore which produces a 



male gametophyte. 152. 

 MICROSPOROPHYLL : a sporophyll which produces only microsporangia. 



152. 

 MICROPYLE: the passageway to the nucellus left by the integument. 



178. 

 MONCECIOUS : applied to plants in which the two sex organs are upon 



the same individual. 115. 

 MONOPODIAL : applied to a style of branching in which the branches 



arise from the side of the axis. 35. 



MOTHER CELL : usually a cell which produces new cells by internal divi- 

 sion. 9. 

 MYCELIUM : the mat of filaments which composes the working body of 



a fungus. 49. 



NAKED FLOWER : one with no floral leaves. 222. 

 NUCELLUS : the main bodv of the ovule. 178. 



