46 REPORT OF THE CONFERENCE ON GENETICS, 
simple, if we may understand that the yellow of the orange B. Suther- 
landi is dropped by the influence of the white B. Dregei, leaving the red. 
Another instance occurs in Rhododendron. 
Showing how readily some quite distinct species may combine in one, 
a plant of Cineraria was exhibited in which, by means of different 
crossings, were combined the common garden Cineraria and all the allied 
species cultivated at different times in the Cambridge Botanic Garden. 
The last Cineraria cross, recently made, bringing an unnamed species 
into the combination, will probably be as fertile as the previous crosses 
have been. 
One of the most interesting plants botanically was a cross between 
Senecio vulgaris and S. squalidus, which is now established as a weed in 
the Cambridge Botanic Garden. It came from near Cork, where it is found 
wild. The “graft hybrid’? Cytisws Adami was shown with two of the 
three forms on one branch. It is understood to have been produced by 
erafting Cytisus purpwreus on the common Laburnum. Both these 
species break out separately on the tree, apparently pure, with a third form 
regarded as the “graft hybrid.” Specimens of Laburnum and C. pur- 
pureus were shown pure, raised from seed gathered from corresponding 
parts of the tree. Other plants shown were Aloe Lynchii, a bigeneric 
hybrid between Gasteria verrucosa and Aloe stricta, and also a cross 
made both ways between A. somaliensis and A. oligospila, no difference 
being evident between the plants whichever way the cross was made. 
Also in this group were Hypericum Moserianum (H. calyeinum x 
patulum) and hybrids of Clematis coccinea with one of the older Clematis 
hybrids, viz. ‘ Star of India.’ 
Exuisit oF HEREDITY IN SNAILS BY PROFESSOR Lana, of the 
University ,of Ziirich. 
Professor Lang, of Ziirich, very kindly sent over the results of his 
breeding experiments with Heiix hortensis and Helix nemoralis. 
The examples sent illustrated two chief experiments. First, the result 
of crossing banded with unbanded individuals of Helix hortensis; and 
secondly, of a cross between Helix hortensis and Helix nemoralis. 
The results of the first experiment could be described in terms of a 
Mendelian formula, inasmuch as they exhibited the phenomena of domi- 
nance and segregation. 
The results of the second experiment were exceedingly interesting, 
partly because they consisted in the production of a hybrid between two 
forms that are universally recognised as distinct species and partly 
because the knowledge obtained by the experiments has a strong bearing 
on the interpretation offered by Contagne of a certain state of affairs that 
he observed in the field. 
If the reader desires further information on this case the two follow- 
ing references, the first to Prof. Lang’s work and the second to an abstract 
in English and a review of it, will be useful to him :-— 
Lang. A. “ Ueber Vorversuche zu Untersuchungen iiber die Varicti- 
tenbildungen von Helix hortensis Miiller und Helix nemoralis L.,” Fest- 
schrift zum siebzigsten Geburtstage von Ernst Haeckel, Jena, 1904, p. 439. 
