Fink: lycopersicum esculentum. 639 



the stigmas came to best condition for pollination; but of the 

 seventy-five flowers only one produced fruit, and this was a 

 flower of the Yellow Plum tomato that had been castrated just 

 after the corolla had expanded. I cannot be certain that this 

 small flower was not accidently pollinated in castrating. Besides 

 the one matured fruit three ovaries started to grow and aborted 

 at about one-fourth the size of a pea. The failure to get better 

 results from castrated flowers, taken with the fact that flowers 

 confined alone under a screen are as uniformly pollinated as 

 those not confined, seemed to indicate that tomatoes are usually 

 close-pollinated; but later results tend to prove that they are 

 not in so many instances as was supposed at first. 



It was thought that the flowers might have been consider- 

 ably injured in castration and that the exposed pistil might 

 have suffered from the heat of the sun. To ascertain the facts 

 as nearly as possible all but one stamen were removed from 

 about fifty flowers. They were nearly as uniformly pollinated as 

 those not treated. This experiment, as well as the fact brought 

 out later that castrated flowers, when pollinated by hand, pro- 

 duce fruit as uniformly as those left to nature, proves that 

 the injury is not considerable. 



The study of the relation of insects to cross pollination of 

 tomatoes was a very interesting one. Various kinds of Coleo- 

 ptera, Diptera and Hymenoptera were observed, but none 

 visited the flowers more than other parts of the plants. I 

 watched for Lepidoptera at various portions of the day, but 

 did not find a single species at work on the tomatoes. I watched 

 the humble-bees repeatedly at work. One or more were in the 

 patch at almost any moment of the day, and sometimes as many 

 as a dozen were working at once. They go from flower to 

 flower, visiting about six in a minute. This slowness as well as 

 the rapid movements of their maxillae and limbs, show that they 

 are gathering pollen. In the work they stand over the top of 

 the stigma, turning themselves about upon it. As the stigma 

 usually extends beyond the stamens it is the more probable that 

 the bees must pollinate some of the flowers. To make sure that 

 they get the pollen I examined different portions of the body 

 under the microscope and found the pollen-grains on every part 

 examined, so that any part of the body coming in contact 

 with the stigma might effect a cross. Besides the pollen scat- 

 tered over the body large masses were found on the posterior 

 tarsi and tibia?. To make certain that this pollen was not in- 

 jured by the bees I gathered the pollen from the posterior 



