386 REPORT OF THE CONFERENCE ON GENETICS. 
M. Labergerie has meanwhile found other variations from the original 
type of S. Commersoni. 
There were some people in France, notably Monsieur Philippe de 
Vilmorin, who doubted whether the blue variety was actually produced by 
S. Commersonii. In all its characters it closely resembled a variety of 
the common potato called ‘Blaue Riesen’ (Blue Giant) raised by a 
German, Herr Paulsen, at Nassengrund, Lippe Detmold. 
M. Labergerie was good enough to send me tubers of his violet variety 
and also of all his others. Of these I gave some to my son-in-law, Mr. 
A. Dreyer, at Plenkitten, Kreis Mohrungen, East Prussia, where he has 
very heavy soil, which our garden in Berlin has not; and a fortnight ago 
I received flowers from him, and I find the calyx teeth of Labergerie’s 
violet variety are exactly as thin and long and hairy as in S. tuberosum, 
the form also of the corolla is quite the same, not deeply incised, not star- 
shaped, as in S. Commersonw. The stigma, too, is capitate or bilobed- 
capitate, not compressed from both sides and bilobed-roof-shaped as in 
S. Commersonit. 
The day before I left Berlin, I noticed in the ‘Gardeners’ Chronicle” 
the same opinion as my own expressed by Mr. Sutton, and by those 
Fellows of the Royal Horticultural Society who had seen the plants 
crowing at Messrs. Sutton’s. On Tuesday, the 31st July, at the fortnightly 
meeting of the Society, Mr. Sutton also exhibited the white type of 
S. Commersonw side by side with the violet variety ; and for comparison, 
the ‘Blue Giant’ from Mr. Paulsen, the breeder, at Nassengrund, Lippe 
Detmold. He also added other wild species, a wild type of S. tuberosum, 
S. Maglia, and S. polyadenium. 
We are all quite sure that M. Labergerie is a man who works with 
ereat care, and his honesty is undoubted; but as to err is human, so we 
were convinced that this was a case in which an error had crept in 
unawares, notwithstanding all precautions, and that a tuber of ‘ Blue 
Giant’ must have been in the soil at the place where he planted 
S. Commersoni. 
Such was my standpoint up to yesterday morning. Then I receiveda 
letter from M. Labergerie, in which he replies to the doubts which I had 
expressed to him before leaving Berlin. He says he has never had the 
‘Blue Giant’ in his garden, and that the plot of ground had, since 1882, 
only been planted with cabbage, salads, and sorrel (Ruwmex Patientia). 
Moreover, his father had grown the ‘ Blue Giant’ in 1894 or 1895 (eleven 
years ago) without success on a plot of ground 10 kilometres distant. 
And when, in 1905, the present M. Labergerie heard people say that it 
and his potato were identical, he bought some tubers of ‘ Blue Giant.’ He 
now tells me that the former has very large tubers, 400-1100 grammes, 
such as are seldom found in S. twberoswm, but are common in S. 
Commersonii Violette. Another thing which he considers is a proof that 
it is not the same is that the stolons have become considerably shortened. 
In 1904 and 1905 he obtained from his S. Commersonii two yellow 
varieties, spotted with violet, or yellow with violet eyes; and also from a 
yellow form of 1908 or 1904 he obtained the same violet type as in 1901. 
He has, moreover, obtained still many other forms, some of these resem- 
bling other common varieties of the potato. 
