NOTES AND ABSTRACTS. 



279 



be excluded from the pits, and "seed" should be procured from 

 localities where the disease has not appeared. — F. J. C. 



Potato as a Truck Crop. By L. C. Corbett {U.S.A. Dep. 

 Agr. Farmers' Bull. AO! ; October 1910).— Potatos are largely grown 

 throughout the United States. In the South two crops are often 

 produced in a single season from Northern-grown seed. The first crop 

 is harvested when the tubers attain a suitable size, regardless of 

 maturity. The second crop is grown from tubers saved from the first, 

 and produces seed which is held over towards the next season's require- 

 ments. It is important in the latter case that the tubers should not be 

 exposed to the sun's rays, or they will not keep, and that they should 

 be fully matured before digging. 



Care should be exercised in spraying, harvesting, and grading the 

 crop. — C. H. L. 



Potato Crop, Considerations and Experiments on the sup- 

 posed Infection of the, with the Blight Fung-us (Phytophthora 

 infestans) by means of Mycelium derived directly from the 

 Planted Tubers, By G. H. Pethybridge. (Sci. Proc. Roy. Diihlin 

 Soc. xih. (1911) pp. 12-27). — The author's investigations which are 

 here recorded lead him to believe that the " hibernating mycelium " 

 theory of the outbreak of attacks of potato disease is untenable. He 

 finds that when diseased tubers are planted they : 



(1) Die before planting-time. 



(2) Die if planted in the ground, without producing any overground 

 stalks. 



(3) Produce small stalks above ground which soon die owing to 

 direct infection with the fungus from the parent tuber. 



(4) Produce healthy plants, which, provided there be no oppor- 

 tunity during the season of becoming infected by aerially borne 

 " spores," remain free from the disease. 



Plants under experiment grown from diseased tubers when kept 

 under conditions which render infection by spores from aerial sources 

 practically impossible remained free from disease as did those derived 

 from healthy tubers. 



The author considers that the principal source of infection of new 

 tubers is the spores of the fungus which fall to the ground, and this 

 may be the only source. The mode of over- wintering of the fungus the 

 author considers is still to be discovered. — F. J. C. 



Potato Disease occurring- in Newfoundland, A Serious. By 



H. T. Giissow {Dep. Agr. Canada, Bull. 63; October 1909).— The 

 occurrence of " warty disease " of potato {Synchytrium endobioticum) 

 in 1909 is recorded, and an outline of the history of the disease is 

 given. — F. J. G. 



Potato, On the Spongy Bodies, Spheres, and Globular 

 Bodies present in the Cells of Bracken (Pteris) and. By A. S. 



