453 STATE POMOLOGICAL SOCIETY. 



pears were slowly becoming of a single hybrid species, or rather series of modi- 

 fications, of the winter pears. The Bartlctts especially are showing the char- 

 acteristics of the winter pears in a remarkable manner, and tlie "piickcry*' 

 taste of the latter is especially observable. It is curious that the active part is 

 taken by the Avinter pears in inlluencing the others, while they tliemsolves, as 

 yet, show no modification. The question is, how could the winter pear exert 

 this predominating influence, not only over the trees in its immediate neighbor- 

 hood, but over others at the opposite end of the enclosure? It is of course, 

 probable that while the trees were in blossom, the pollen of the winter pear 

 flowers was transported to the flowers of the other trees. The phenomenon 

 is in any event doubly suggestive ; first, in that it is an instance of a new vari- 

 ety being gradually formed by the action of nature ; and second, in that it 

 indicates to fruit growers tiic danger in placing fine pear trees in proximity to 

 those of inferior variety. 



NATURAL ROTATIOX OF PLANTS. 



In relation to the natural rotation of plants, M. Dureau de la Malle in 1825 

 called attention to this natural phenomenon. He found that in pastures the 

 grasses get the upper hand for a time, then the leguminous plants, so that in 

 thirty years the author was witness to five or six such alterations. Dean Her- 

 bert has called attention to the fact that a plant does not necessarily grow in 

 the situation best adapted to it, but where it can best hold its own against hos- 

 tile neighbors, and best sustain itself against unfavorable conditions generally. 



Investigations have made it apparent that forests also have their natural rota- 

 tion ; deciduous trees succeed coniferous ones, hard woods soft woods, etc. But 

 it is not as stated by Dean Herbert. Certain trees and plants do occupy certain 

 soils and situations, and to the exclusion of others ; and, as a rule, those soils 

 and situations best adapted to them. It would have been better stated to have 

 said that trees and plants do not always occupy those situations best adapted 

 to them. 



NATURAL DISPERSION OF PLANTS. 



Statistics relating to the distribution of the flora of Europe, reach a curious 

 conclusion, and which will apply without doubt to other countries. It is, that 

 those plants having seeds or fruit with special appendages to aid in their disper- 

 sion are generally less widely scattered tlian those destitute of such helps. The 

 single exception is in the cases of seeds provided with a tuft of hair, — techni- 

 cally termed coma, — which have a very broad range, Tiie seeds of the wil- 

 lows and those of the milk weeds are furnished witii tlie coma. Dr. Gray states 

 that these last plants, which are "the most comosc-seeded of the higher 

 orders," have not a wide range in North America. It is also found, from a 

 study of the European flora, that plants whose flowers bear l)ut a single seed, 

 are more broadly distributed than tiiose bearing two or more seeds in each cell. 

 Plants with albuminous seeds somewhat sur])ass in range the ex-albuminous, — 

 a singular fact, considering the ex-albuminous seeds have the longest known 



