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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 (Pinus): A, section of cone, showing 

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

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

 men, showing the two sporangia; D, 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 Stkasbukgbb. 



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 



