408 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



The hope that varieties of potatoes may be found practi- 

 cally disease-proof is based upon the assumption that there 

 is a definite period of incubation of this disease at certain 

 seasons, and that certain varieties reaching maturity before 

 this period, or after it has passed, may avoid its attack. 



Professor De Bary, of Strasburg, has received the grant 

 of 100, and entered upon the desired investigation. 18-4, 

 December 26, 1873, 353. 



ONE CAUSE OF THE POTATO DISEASE. 



Among the numerous causes of the potato disease, accord- 

 ing to Dr. Alfred Carpenter, a principal one consists in the 

 accidental introduction of a diseased tuber into a pile des- 

 tined for subsequent planting, the spores being transmitted 

 from one to the other, so that the entire mass is more or less 

 affected. Dr. Carpenter thinks that, as a general rule, the 

 germs of disease must be pre-existing in the mother plant, 

 but that they may remain entirely dormant or altogether in- 

 active for a considerable period, or until favorable conditions 

 of excessive moisture, heat, or other causes combine in proper 

 ratio to quicken their growth. If measures can be taken to 

 completely disinfect the seed-potato before planting, he thinks 

 no apprehension need be felt as to the future. Jour, of Bath 

 and West of Eng. Agric. Soc, 1873, 73. 



THE HOOrBEEUK SYSTEM OF FRUIT-CULTURE. 



A year or two ago Les Mondes published an account of 

 what was called the Hooibreuk process of fruit-culture, so 

 named from its discoverer, an ignorant peasant on the Dan- 

 ube. This consists, essentially, in training the branches of 

 fruit-trees, vines, etc., so as to give them an inclination be- 

 low the horizontal line; in which case there is a great in- 

 crease in the fertility of the branch, which, in fact, throws out 

 leaves and fruit buds in an extraordinary manner. An es- 

 sential condition of the process consists in having the line of 

 the branch nearly straight; as, if curved, only the buds at 

 the top of the arc are developed, while the rest remain in 

 their original condition. 



Duchesne-Thoureau, by whom the information was first 

 communicated to Les Mondes, was of the opinion that the in- 

 creased vigor of the branch thus treated was caused by its 



