NEW YORK EXPERIMENT STATION BULLETINS. 347 



ence of the Michigan growers has proved conclusively that radical meas- 

 ures will keep the disease in check or almost eliminate it from an country. 

 The New York law is essentially the same as the Michigan law, and if it 

 is rigidly enforced by healthy public sentiment, there is no reason why 

 peach culture should not nourish. Otherwise, sooner or later our peach 

 industry must perish. 



EXPERIENCES IN CROSSING CUCURBITS. 



The limits and results of crossing cucurbitaceous plants — pumpkins, 

 squashes, melons, cucumbers — are little understood. The common notions 

 are exceedingly vague. It is nearly everywhere supposed that all the 

 species intermingle indiscriminately, and any statement to the contrary is 

 likely to meet with incredulity. Yet there is reason to believe that many 

 of the common observations concerning these plants are incorrect. All 

 the species are exceedingly variable, and it is easy to select fruits from 

 large plantations which bear some external resemblance to fruits of other 

 species, and it is natural to suppose, in the present confused state of our 

 knowledge of hybridity, that such f j ijts are hybrids. 



I began definite experiments in crossing cucurbits in 1887, and selec- 

 tions and close observations were begun before that time. The work has 

 been continued upon a large scale, and I have now made fully 1,000 careful 

 hand pollinations, and have obtained no less than 1,000 types of pump- 

 kins and squashes never recorded. The plantations of selections and 

 crosses covered some eight acres this year. 



The experiment is only begun. The main results of it can not be 

 announced until further work has been done. But some of the incidental 

 features of the research can be stated from time to time. 



1. Immediate effect of crossing. — The "immediate effect of crossing" is 

 a term used to denote any change which may occur in the fruit the same 

 year the cross is made, as a result of the influence of pollen. Whatever 

 effect the pollen may have is usually shown in the offspring of the crossed 

 fruit rather than immediately the same season in the fruit itself. There 

 are but few plants in which an immediate effect of crossing has been 

 proved, and of these Indian corn is the most familiar. It is commonly 

 said that it occurs in pumpkins and squashes, also ; but it certainly does 

 not. There has never been any immediate influence whatever in any of 

 our crosses, except such as was due to imperfect development caused by 

 insufficient or impotent pollen. In other words, the effects of the cross 

 are seen only in the offspring of the fruits. 



It is easy to prove, without the aid of artificial pollination, even among 

 the most variable squashes, that there is no immediate" effect. If there 

 were an immediate effect, all the fruits upon a vine would be likely to be 

 different, as every one would probably receive a different pollination. 

 This diverse pollination would almost inevitably result if many varieties 

 were planted close together, for the flowers of pumpkins and squashes are 

 imperfect and can not pollinate themselves. But the fact is that all the 

 fruits on any vine are alike, with some trifling exceptions in rare cases 

 due to arrested development or the like; the essential characters of the 



