210 M. MIYOSÖI. 



the same place without noticing a single insect, and most stigmas 

 were o|)en. 



During these days I likewise examined tlie same species in the 

 Botanic Garden of the University at Koishikawa. and found almost 

 the same state of things. 



In all cases I observed that those growing in shady places and 

 those kept in the house had their stigmas always open, while those 

 on open sunny lawns had the parts mostly closed, — the differences 

 seeming to be due to the relative frequency or total absence of the 

 in sect -vi si tors. 



These insect-visit(3rs belong almost exclusively to the Hymeno- 

 ptera, a species of Eucera (PI. XXVIII. Figs. 4, 5) of Apidœ, 

 identified for me by Dr. C. Isliikawa, being the chief visitor. The 

 visit of this bee, however, is not confined to the flower of Mazus, for 

 I often noticed that the insect burdened with yellow pollen dusts of 

 other flowers, probably of Taraxacum, thrust its body into the lips of 

 the flower smearing the stigma as well as the corolla with the golden 

 yellow powder. 



So far as my observation extends, I may conclude that the 

 iri-italjility of the stigma of this plant is not for the pm-pose of 

 protection against wind and rain, of which the stigma may be 

 tolerably well kept out by the overhanging n[)per lip of the corolla, 

 but — as has been suggested by Hermann Müller* in the case of 

 Miinulm liiteus — for a more important purpose, i.e. ïov cross-fertiliza- 

 tion, which no doubt takes place in the following manner. 



A bee laden with the [)olleu of one flower enters another flower 

 of the same species for honey, and thus comes with its liead in 

 contact Avith the lower lobe of the stigma which just overhangs the 



* Die Befruchtung der Blumen druch Tnsecton und die ireoenseitig-eu Anpassungen beider. 

 Leipzig, 187:î. 



