Referate. 28q 



6'. Cii/Jasü, S. Fernandezianiiiii, S. Bridgcsii and ^'. etiiberostnn Lindley. In a 

 third group, like the second in calyx form, but differing from it in having 

 deeply five-parted star-shaped coroUas, he places -S". Commvrsonii, S. Ohrondi, 

 S. cardiophylluii! and 5. Jamesii. 



To support these claims a considerable amount of interesting historical 

 data IS cited. But as the history of the potato is more or less familiar 

 from the exhaustive work of Roze, the interest of students of heredity 

 centres around the use he makes of the classification, granting its validity. 

 His first attack is upon the recent work of A. W. Sutton, upon 5. efuberosum. 

 He points out that the tuberless plant, from the seed of which Sutton 

 raised tuber bearing plants, is nothing but a S. tuberosum and quite different 

 in its characters from Lindley's type plant. His second criticism is directed 

 toward the 5. Commersonli violett of Labergerie. The author sis has given 

 considerable time and study to his preparation of this discussion, and no 

 one could ask for a more judicial consideration than Labergerie receives 

 at his hands. The facts appear to be as follows. 



Ed. Heckel of Marseilles gave some tubers of typical .S'. Comwersonii 

 to J. Labergerie of Verrieres. During several years culture at Marseilles, 

 these tubers continued to produce typical S. commersomi. At Verrieres in 

 igoi, however, Labergerie found one plant with a thick stalk and short 

 stolons that produced- violet-colored tubers. These tubers, in succeeding 

 years, have produced crops far exceeding any that A". Comnwrsonil has been 

 known to produce. They have shown a certain amount of variation but 

 no reversion to the typical .S'. Comuiersonii. In shape of fruit, size of tuber, 

 color of tuber, color and shape of corolla, and shape of calyx, these plants 

 are exactly like a commercial variety of S. tuberosum known as Paulsen's 

 Blue Giant. Either a combination of mutations in all of these characters 

 occurred in igoi, or there has been a mixture with S. tuberosuvi. Labergerie's 

 work has been apparently been carelul, yet there is not absolute certainty 

 that such a mixture has not occurred. He himself had not raised the 

 Blue Giant, but his father several miles away had done so a number of 

 years before the supposed mutations appeared. It also appears that owing 

 to the dry mild climate at Verrieres, potato tubers might have remained 

 in the soil for some time and finally have produced plants. No bud 

 mutations in so many characters has ever been known before and scientists 

 are not likely to approve this case unless it can be shown beyond question 

 that the violet tubers came from S. Commersomi. Absolute proof of this 

 fact would entirely upset our conception of bud variations, and until such 

 proof is forthcoming, biologists will remain unconvinced. 



It might be remarked that the reviewer obtained some tubers of 

 Labergerie's stock imported by J. J. H. Gregory & Son, Marblehead, 

 Massachusetts in 190b. After observing the plants for two seasons, the 

 following statement was made in an article entitled „A study of the 

 factors influencing the improvement of the potato" : ,,I am compelled to 

 state that in no character of leaf, stem, flower or tuber, is the plant 

 different from common purple-tubered varieties of S. tuberosum". 



The author also devotes some space to a discussion of the symbiosis 

 theory of tuber production, but as the burden of proof still remains with 

 the jjropounders of the theory, it seems scarcely worthy of scientific 

 consideration. E. M. East, Harvard University. 



liKiiiklivc Al)*tammiing%- (mil Vererbungslehre. III. 19 



