SEXUAL EEPRODUCTION. 181 



perhaps they might be thought to perform the part of andro- 

 spores, attributing to that expression the meaning which 

 Pringsheim gives it in the ConferocB. The experiments per- 

 formed with the spermatia which do not germinate, and with 

 the spermogonia of the Uredines, do not, at any rate, appear 

 to justify the reputed masculine or fecundative nature of these 

 organs. The spermogonia constantly accompany or precede 

 fruits of 2Ecidium, whence naturally follows the presumption 

 that the first are in a sexual relation to the second. Still, 

 when Tulasne cultivated TSndophyllum sempervivum, he obtained 

 on some perfectly isolated rosettes of Sempervivum some JEcidium 

 richly provided with normal and fertile spores, without any trace 

 of spermogonia or of spermatia. 



