188 REVIEWS. 



In France alone they count about 800 sorts of pears ; the 

 origin of most of them is unknown, and many are undoubtedly 

 very ancient. Indeed, according to Jordan and his school 

 these differences are primitive, and the so-called races and 

 varieties, both of wild and cultivated plants, represent so many 

 closely related species. But M. Decaisne, not content with 

 the rcductio ad absurdum of having about 2000 species of 

 pears to be dealt with, proceeded to an experimental demon- 

 stration of the variability of the cultivated races. He sowed 

 the seeds from four very distinct varieties in 1853, the Poire 

 d'Angleterre, the Bosc, the Belle Alliance, and the Cirole. 

 Of the last the four trees raised bore fruit of four different 

 forms. From the Belle Alliance he obtained, in this first 

 generation, nine new varieties, none of them representing the 

 parent, neither in the form, size, color, nor even the time of 

 ripening of the fruit. The Bosc equally produced new varie- 

 ties. Of the Angleterre nine trees produced as many new 

 forms, one of them a winter-pear similar to the Saint Ger- 

 main, another apple-shaped fruit identical with one which 

 was raised from the Belle Alliance. On plate 33, Decaisne 

 gives figures of six different pears raised from the Angleterre. 

 These results even led him to doubt the cases cited by Darwin 

 of the reproduction of certain pears from seed. He insists, 

 moi'eover, that very bad fruits may be raised from choice cul- 

 tivated pears, and that good varieties may be obtained from 

 the seeds of wild pears. The latter is not what one would 

 expect in the first generation. 



Our author proceeds to state that the trees raised from seed 

 taken from the same fruit differed, not merely in their fruits 

 and in the time of ripening, but no less in their flowers and 

 in the form of the leaves. Some were thorny, others thorn- 

 less ; some produced slender shoots, others thick and stout 

 shoots, etc. It is worth noticing, however, that no mention is 

 made of any precautions to prevent cross-fertilization of the 

 flowers from which the seeds planted were derived, which 

 might have influenced the product through the now well-ascer- 

 tained influence of the pollen upon the pericarp. We per- 

 ceive, however, that he would regard this as unimportant, 



