336 Schively — Contributions to the Life History of 



Microspores and Macrospores. 



Little has been said concerning the pollen ; it seemed 

 best to compare all flowers in this particular at one time. 

 When young the anthers of the purple flozvers are quite 

 well filled. The appearance of pollen after the anthers 

 have dehisced has already been described. Dr. Macfarlane in- 

 forms me that it resembles the inefficacious pollen of certain 

 hybrids. It measures when dry, 13 /i, upon addition of 

 water it measures 16-18 /i. 



The anthers of the green aerial flower do not contain so 

 much pollen as those of the purple flower ; it resembles in 

 appearance the pollen of the latter when water has been 

 added. It is pale yellow, granular, and measures 1 1 p. 



The pollen of the terrestrial flozvers is less abundant 

 than that of the last ; but the appearance is similar ; it 

 measures 8-9 fi. Two nuclei are frequently seen in this 

 pollen grain. (Plate XXIX., Fig. 5.) 



I can not state so certainly the comparative size of the 

 macrospores, as I do not feel sure that those measured were 

 absolutely at the same stage — namely, ready for fertiliza- 

 tion. From specimens which have been examined, the 

 macrospore in the purple flozver measures 5 /j ; that of the 

 green aerial 6 //, and that of the terrestrial 4 ju. 



Before turning attention to the legumes, it may not be 

 out of place to refer to the comparative size of the pistils 

 of the three types of flowers, as shown in Plate XXXII., 

 Figs. 2, 3 and 4. 



Histology of Legumes. 



The macroscopic appearances of the legumes have already 

 been described, and reference to illustrations will convince 

 the reader that it is not easy to mistake the products of the 

 different flowers. It is possibly not scientifically correct to 

 apply the term "legume" to the fruit of the terrestrial 

 flower, as there is no dehiscence ; but considering it as a 

 modification of the others, the expression may, perhaps, be 



