4 BULLETIN 289, U. S. DEPARTMENT OF AGRICULTURE. 



question whether or not red clover is self-fertile, according to Smith 

 (38, p. 236). 



Garton, according to Wallace (44), claims that red-clover flowers 

 are cloistogamous, but Martin (26) in his work on the cytology of 

 red-clover flowers disproved this theory. Garton attempts to prove 

 that the flowers are cleistogamous by saying that the ovules are 

 well formed by the time the flowers open. The ovary is quite large 

 at this time, and it was undoubtedly taken to be a developing ovule. 

 Pammel and King (32) record that self-fertilization was accomplished 

 in some experiments at Ames, Iowa, by irritating the stigmas. Hunt 

 (19) speaks as follows: "It has long been recognized that red-clover 

 and other leguminous flowers may bo self -pollinated, although it 

 has never been determined whether self-pollination or cross-pollina- 

 tion most commonly occurs." 



According to Dunning (8), after the introduction and establish- 

 ment of bumblebees in New Zealand red clover seeded abundantly, 

 but previous to this time he says it seeded very little. The Agri- 

 cultural Gazette of New South Wales (9, 16) maintains that bumble- 

 bees were introduced into New South Wales from New Zealand so 

 that they would be able to produce clover seed for home use, which 

 up to this time was largely imported. At Failford, New South 

 Wales, red clover seeded abundantly (35), although no bumblebees 

 had been noticed in that vicinity. The pollinating was thought to 

 have been done by several native insects. This was several years 

 after the introduction of bumblebees. Later (17) it was stated that 

 bumblebees had become well established. 



Waldron (41, 42) found in his experiments that bumblebees were 

 responsible for about 95 per cent of red-clover seed and that a small 

 quantity may be produced by natural self-pollination. 



Muller (29, p. 184-186) states that when a bee draws its proboscis 

 out of a clover flower cross-pollination is assured and self-pollination 

 may also take place, but that the self-pollination is probably neutral- 

 ized and superseded by the immediately preceding cross-pollination. 



Folsom (10, p. 116) considers the Italian race of honeybees as 

 important as the bumblebees in clover-seed production, while Arm- 

 strong (1) claims that honeybees are able to extract nectar from 

 red-clover flowers in New Zealand. Pammel (31, p. 172) shows that 

 honeybees are able to collect pollen from red-clover flowers and 

 thereby cross-pollinate them. Robertson (33, p. 177) states as 

 follows: "But while butterflies may sometimes effect cross-fertili- 

 zation of the red clover, they are of doubtful value, if not injurious. 

 * * * But butterflies can insert their thin tongues without 

 depressing the keel, and, even if they get a little pollen on their 

 I hin probosoides, it is apt to be wiped off by the closely approxi- 

 mated tips of the petals, which close the mouths of the flowers," 



