392 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



in general, finer. It is best prepared by throwing the leaves 

 into boiling water, and, after pouring this off, cooking it as 

 usual. Its cultivation is simple. The seed may be sown in 

 a hot-bed in March, for subsequent transplanting, or in the 

 open ground in April or May. 9 C, December, 1874, 183. 



BEST SHAPE FOR FRUIT-TREES. 



The majority of a convention of German pomologists ex- 

 pressed a decided preference for the pyramidal form for fruit- 

 trees. The advantages claimed for it are the minimum of 

 shade, greatest strength, avoidance of severe wounding of 

 the tree, production of better fruit, and at the same time 

 fewer disadvantages from storms, weight of snow, excess of 

 fruit, theft, etc. 5 (7, July, 1874, 105. 



NEW FACTS IN THE HISTORY OF THE POTATO BLIGHT. 



Aii important step has been gained in the natural history 

 of the potato blight. It is stated that Professor De Bary, of 

 Strasburg, has detected the existence of " hetersecism," or 

 an "alternation of generations," in the life history of the Pe- 

 ronospora infestans, the parasitic fungus which causes the 

 disease. It is conjectured that the second form may pos- 

 sibly be found on clover. 



INVESTIGATION OF THE POTATO DISEASE. 



Announcement has already been made of the selection of 

 Professor De Bary, of Strasburg, by the Royal Agricultural 

 Society of England to make a series of investigations into 

 the life history of the potato fungus, for the purpose of filling 

 up a certain blank in our knowledge of the development of 

 this destructive object. This gentleman, in carrying out his 

 investigations, has lately discovered that the disease is not 

 propagated by defective tubers, and that although the myce- 

 lium was distinctly apparent in the stalks of plants raised 

 directly from diseased tubers, yet that neither gonidia nor 

 germs were evolved. He also expresses the hope that he has 

 at last discovered the resting-places of the oospores, or the 

 active primary germs of the fungus. This is the special 

 point upon which further information is needed, and may 

 suggest the proper means of preventing the continuance of 

 the disease in any given locality by warning agriculturists 



