FERTILIZATION AND CROSS-FERTILIZATION. 83 



are not so much capable as others of fertilizing themselves. Why 

 do we plant each variet}' of corn and squashes by itself, but to 

 keep the variety from fertilization by others ? 



The Chairman referred to the various contrivances described by 

 Prof. Goodale for preventing self-fertilization in orchids. 



Mr. Wilder said that varieties were so likely to be impregnated 

 by pollen floating in the air, that when we would fertilize a flower 

 with the pollen of a particular variety, we must cover the stj'le 

 with gauze to prevent fertilization by other than the desired pollen. 

 When we want to raise a seedhng possessing the good points of a 

 weak growing variety, but with greater vigor, we impregnate with 

 the pollen of a strong grower ; or if we have an excess of vigor, which 

 it is desired to reduce, we reverse the process ; and when we have 

 gained the desired improvement, if we keep the plant separate from 

 others we have the same variety to the end of time. The longer he 

 lived the more was he impressed with the importance of cross impreg- 

 nation, and the more convinced that it is the best way to obtain 

 great improvements. We cannot rely on accidental impregnation 

 for them. Providence seems to have placed in our hands all the 

 data we need for originating improved varieties. Mr. Wilder 

 referred to a paper on h3'bridization, by Mr. Herbert, published in 

 the "Journal of the London Horticultural Society'," Vol. II, pp. 1 

 and 81, as covering the whole subject of the improvement of 

 varieties. 



Edward S. Rand, Jr., asked for any well authenticated fact in 

 relation to the crossing of two well defined species. 



Mr. Wilder said that the question was too strict, botanists not 

 being agreed as to what constitute species. The rhododendron and 

 azalea have usually been classed as distinct genera, and yet they 

 cross readily. 



Mr. Rand replied that he supposed Mr. Wilder referred to 

 gesneraceous plants, but« that he had yet to learn of the crossing 

 of two well defined species. He did not consider the rhododendi'on 

 and azalea weU defined genera. 



Leander Wetherell said that the different species of the lily, when 

 growing wild, perpetuate themselves without variation of kind, but 

 when cultivated they produce varieties. The same is true of 

 animals, and he named the Ancon breed of sheep as an instance. If 

 you wish to produce a vigorous race, cross-fertilization is essential. 

 Darwin says that if you wish to perpetuate any peculiarities in a 



