462 BOTANICAL GAZETTE 



[JUNE 



the plants associated with it, even if perennials, are not very sturdy 

 competitors, but mostly of gregarious habit also. At Oregon they 

 were chiefly Lechea tmuifolia, Talinum teretifolium, Selaginella 

 ' stris, Silene antirrhina divaricata; in the dunes of Indiana, 

 \ia virginica, Arab is lyrata, Viola pedata, Polygonella articulata, 

 Festuca octoflora. But to whatever extent the time of fruit- 



P 



in such habitats. 



com 



com 



and being an annual or fall-biennial, soon accomplishes its life- 



* m * rf~v «4 I m 



work. 



That the cross-pollination of the earlier and larger flowers of 

 L canadensis must also be much to its advantage, in increase of 

 vigor and productiveness, is evident from the nature of this process. 



This was clearlv nmvpn k« rw««r™ • 1 • . . , , 



arwin in his experimental 



cross- and self-fertilized plants. Of two beds of L. vulgaris, raised 



respectively from self-fertilized and crossed seedlings, those of the 



latter were seen to be much more vigorous. This led him to trials 



with this and other plants, the results of which are given in his book 



upon this subject. The case of Linaria needs only to be cited. As 



showing the vigor, « the naturally crossed plants were to the spon- 

 taneouslv splf-fprtn;™^ ~i — <_ • i • , . 



81." 



fruitfulness similar results came from 



~ - ~ "u^uiuto buuiiar results came trom the two 



modes of treatment, that of allowing or preventing the visits of bees. 

 I he number of seeds in the capsules on the exposed plants to the 

 average number in the finest capsules on the protected plants was 

 as 100 to 14," or as expressed by him in a summary of plants so 

 treated, the self-fertilized were "extremely sterile.'"* Knuth is 

 even more emphatic in stating that though self-pollination is possible 

 and can occur spontaneously in L. vulgaris, it is of little conse- 

 quence or w,thout result." In cases of this kind, where pollination 

 trom without and within takes place simultaneously, Hermann 



MtJLLER 



in its 



~ . , ■ r »«n iuc luixuer preponderates 



effects, and that the desired result is secured in this way." 



3(>3- l8?£* mW ' ° "• Cr ° SS and Self " fertilization in the vegetable kingdom 88, 89, 



16 Knuth, Blumen und Insekten auf dem nordfriesischen Inseln in. 1894. 

 »» Muller, Befruchtung der Blumen 279. 



t 



