AGRICULTURAL EXPERIMENT STATION. 



43 



According to Hildebrand,* in the case 

 of several orchids the plant's own pollen 

 is necessary for the development of the 

 ovarium ; and this development takes place 

 long before the pollen tubes have reached 

 the ovules. So in these cases the pollen 

 acts directly on the ovarium. 



Disregard of the fact discovered by 

 Camerarius, but not emphasized by him, 

 that certain dioecious plants occasionally 

 have monoecious individuals, has lead to 

 many erroneous statements regarding the 

 influence of the male element on the ovary. 

 Hemp and Spinach have been cited f as 

 examples of development without fertiliza- 

 tion. It is well known, however, that 

 both of these species have monoecious 

 individuals, thus furnishing a source of 

 error in observation. The Muskmelon, 

 Cxicumis melo, is another instance in point. 

 This fact first attracted my attention when attempting to per- 

 form some artificial hybridizations between Gucumis melo and 

 Cucumis sativus. The female blossoms on the variety under con- 

 sideration, " Emerald Gem," were found to bear partially devel- 

 oped stamens. These stamens varied in size and in the amount 

 of pollen produced, but subsequent developments indicated that 

 enough pollen may be produced to secure self-fertilization. At 

 the Cornell University Experiment Station several blossoms of 

 this variety from which foreign pollen was excluded developed 

 apparently normal fruits. In these cases of probable self-fertil- 

 ization, however, there were no perfect seeds. 



Darwin cites, on the authority of Dr. Hooker, an instance of 

 the development of the ovarium of a certain orchid — Bonatea 

 speciosa — as a result of simple mechanical irritation of the stigma. X 

 So far as I am aware, this observation has never been verified, 



Fig. 4. Lima Bean, Seedless 

 (Natural Size.) 



*Botanische Zeitung, No. 44 et. seq. Oct. 30, 1863, and Aug. 4, 1865— cited by Dar- 

 win, An. and Pits. Under Domest. I, 434. 



tLe Maout and De Caisne, System ot Botany, 152; also Spallanzani, quoted by 

 Sachs, Hist, of Bot. 424. 



JAu. and Pits. Under Domest, I, 434. 



