278 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
ATTEMPTED HYBRIDISATION OF DIOSCOREA. 
Wir A View TO OBTAINING A VARIETY OF CHINESE YAM (D1I0ScOREA 
BATATAS) WITH A SHoRT TUBER PERMITTING OF EAsy EXTRACTION 
FROM THE SOIL. 
By Monsieur P. CHaprELLiER. 
I HAvE chiefly fertilised the female Yam of Decaisne (D. Decaisneana) 
which has a spherical tuber with a production almost nil, with the pollen 
of the Chinese Yam (D. batatas) having a very long tuber. 
I have even attempted—in extremis !—to cross D. pyrenaica, a pigmy, 
with D. batatas, a giant, but, as was to be feared, this hazardous attempt 
yielded me no result. 
My experiments, pursued for ten years, have given me a_ great 
number, several thousands, of young plants with tubers of varied forms, 
sometimes irregular and inconstant. Nevertheless, several of my hybrids 
among the more recent ones appear to advance towards the desired end. 
Some plants carry from four to eight tubers not exceeding 45 centimetres 
in length, whilst the tuber of the Chinese Yam is normally single, and 
attains a length of 80 centimetres to 1 metre. 
One of the individuals obtained in the course of my experiments 
produced at one and the same time male and female flowers. 
The seeds have not germinated, and this variation has not been 
maintained. 
