CHAP. X. PLANTS FERTILE WITHOUT INSECT-AID. 369 



flowers ; as they crawled into them, they rubbed against the 

 bristles which project from the anthers, and became dusted 

 with pollen. 



Veronica agrestis (Scrophulariacese). Co vered-up plants produced 

 an abundance of seeds. I do not know whether any insects 

 visit the flowers ; but I have observed Syrphid repeatedly 

 covered with pollen visiting the flowers of V. hedercefolia and 

 chamoedrys. 



Mimulus luteus (Scrophulariaceso). Highly self-fertile. 



Calceolaria (greenhouse variety) (Scrophulariacese). Highly self- 

 fertile. 



Verbascum thapsus (Scrophulariacese). Highly self-fertile. 



V. lychnitis. Highly self-fertile. 



Vandellia nummularifolia (Scrophulariacese). Perfect flowers 

 produce a good many capsules. 



Bartsia odontites (Scrophulariacese). Covered- up plants produced 

 a good many seeds ; but several of these were shrivelled, nor 

 were they so numerous as those produced by unprotected 

 plants, which were incessantly visited by hive and humble- 

 bees. 



Specularia speculum (Lobeliaceae). Covered plants produced 

 almost as many capsules as thf uncovered. 



Lactuca sativa (Composite). Covered plants produced some 

 seeds, but the summer was wet and unfavourable. 



Galium aparine (Kubiacese). Covered plants produced quite as 

 many seeds as the uncovered. 



Apium petrosdinum (Umbelliferse). Covered plants apparently 

 were as productive as the uncovered. 



Zea mays (Graminese). A single plant in the greenhouse 

 produced a good many grains. 



Canna warscewiczi (Marantace). Highly self-fertile. 



OrcMdacece. In Europe Ophrys apt/era is as regularly self- 

 fertilised as is any cleistogamic flower. In the United States, 

 South Africa, and Australia there are a few species which 

 are perfectly self-fertile. These several cases are given in 

 the 2nd edit, of my work on the Fertilisation of Orchids. 



Allium cepa (blood red var.) (Liliacese). Four flower-heads were 

 covered with a net, and they produced somewhat fewer and 

 smaller capsules thar those on the uncovered heads. The 

 capsules were counted on one uncovered head, and were 289 

 in number ; whilst those on a fine head from under the net 

 were only 199. 



2 B 



