176 



PLANT STRUCTURES 



The strobilus composed of microsporophylls may be 

 called the staminate strobilus that is, one composed of 

 stamens ; it is often called the staminate cone, " cone " 

 being the English translation of the word "strobilus." 

 Frequently the staminate cone is spoken of as the "male 

 cone," as it was once supposed that the stamen is the 



FIG. 146. Staminate cone (strobilus) of pine(Pmws): A, section of cone, showing 

 microsporophylls (stamens) bearing microsporangia; J5, longitudinal section of a 

 single stamen, showing the large sporangium beneath ; C, cross-section of a sta- 

 men, showing the two sporangia; Z>, a single microspore (pollen grain) much en- 

 larged, showing the two wings, and a male gametophyte of two cells, the lower 

 and larger (wall cell) developing the pollen tube, the upper and smaller (genera- 

 tive cell) giving rise to the sperms. After STRASBUBGBB. 



male organ. This name should, of course, be abandoned, 

 as the stamen is now known to be a microsporophyll, which 

 is an organ produced by the sporophyte, which never pro- 

 duces sex organs. It should be borne distinctly in mind 

 that the stamen is not a sex organ, for the literature of 

 botany is full of this old assumption, and the beginner is in 



