ON BIASTREPSIS IN ITS RELATION TO CULTIVATION. 157 



were made with my twisted breed of Dipsacus sylvestris. As I have 

 already remarked, this breed, with proper treatment, gives a progeny 

 30-40 per cent, of which have wenmari<ed twisting of the main 

 stem, besides other individuals which show less marked twisting 

 of the branches and others again which have their leaves in whorls 

 of three, if, however, the treatment is unsatisfactory as regards 

 any one of the essential conditions mentioned above, this high per- 

 centage of monstrous forms is not obtained ; there may, in fact, be 

 none at all. 



The scientific results of my experiments may be summed up by 

 saying that Biasfrepsis, especially in the case of Dipsacus sylvestris, 

 is in a high degree dependent upon the conditions which obtain during 

 and subsequently to the germination of the seed. Conditions which 

 favour the vigorous development of the plants promote also the size 

 and the number of the portions of the main stem and of the branches 

 which show the twisting. 



The practical result of my experiments is, I consider, the recog- 

 nition of the fact that the cultivation of monstrosities should either 

 be carried out strictly according to rule or not be attempted at all. 

 Without the requisite care the attempt only results in doubt being 

 cast upon the goodness of the seed and the hereditary properties of 

 the breed. 



I treat of the subject under the following heads: — 



A. The normal cultivation of the breed. 



B. The influence of space. 



C. The influence of the soil. 



D. Summer-sowings. 



E. Autumn-sowings in the open. 



F. Autumn-sowings under glass. 



G. Cultures in other Botanic Gardens. 



A. The normal cultivation of the breed. 



in my monograph on the subject (1891), to which allusion has 

 already been made, I have given an account of the morphology of 

 biastrepsis in Dipsacus sylvestris and of the means by which I 

 obtained the hereditary breed. I was then in a position to report 

 upon the first four generations of this biennial; I now give the re- 

 sults of my observations on the subsequent generations. 



My breed was derived from two individuals with a twisted main 



