Chaiilier horseshoe. — A new horseshoe introduced iu Paris by 

 M. Chailier has been favorably received. It consists of a narrow rim 

 of iron, thoroughly protecting the edge of the hoof without cra'mping 

 its sole in the least. The material to be used must be of the best quality, 

 but the weight being considerably less, the cost is not increased. Thou- 

 sands of horses of the many i)ublic conveyances in Paris have been 

 provided with these shoes, autl they give general satisfaction. 



The European plane-tree in cities. — Xo tree resists so well the 

 smoke and impure air of European cities as the plane, {Platanus occi- 

 dentalism) although it is not a native of that continent. It is the tree 

 niost generally seen in the churchjards, squares, and other open spaces 

 in London, thriving well, and living to a considerable age. This is 

 probably in part due to the fact of the outer layer of bark being shed 

 yearly, and thus not becoming choked with smoke so that its functions 

 are destroyed. The rows of young plane-trees planted along the re- 

 cently opened portion of the Thames embankment, from the Houses of 

 Parliament to Charing Cross and the Temple, are growing vigorously, 

 and i^romise in a few years to afford a grateful shade, and to add much 

 to the beauty of the banks of the river. 



Eeport on the potato disease. — The Prussian Agricultural 

 Academj^ has been occupied since 1863 in making laborious investiga- 

 tions into the mode of propagation and possible prevention of the potato 

 disease. A report of operations has recently been published, from which 

 it appears that the following points, among others, may be considered 

 as iinally determined: First. A relationship and connection between 

 the disease of the leaf and of the tuber, and the fact that the potato- 

 fungus is the cause of the wet-rot of the potato. Second. The wintering 

 of the mycelium of the fungus in the diseased tubers is considered well 

 established and as needing no further verification. The mode of dissem- 

 ination of the disease, however, is considered as requiring additional 

 investigation, including the development of the mycelium of the infected 

 tubers in the suiierficial portion of the young plant, as well as the for- 

 mation of the leaf fungus. The inquiry is suggested also whether the 

 first traces of the leaf disease in the summer come from the mycelium 

 of the infected seed-potatoes of the jirevious year. Experiments are 

 also i:)roposed for ascertaining whether, if the young plants are com- 

 pletely protected from the entrance of fungus-spores from the exterior, 

 a diseased mother bulb would produce diseased plants. The effort to 

 find some convenient mode of disinfection of seed-potatoes for the pur- 

 pose of preventing the disease has not, so far, met with any satisfactory 

 result. It is possible, of course, to destro^^ the mycelium of the fungus 

 iu the tuber by various means; but this generally injures the bud at the 

 same time and prevents its growth. » 



One ver}' important feature accomplished by these inquiries is the 

 ascertaining that different varieties of potatoes vary extremely iu their 

 susceptibility to disease, some kinds being much easier of infection than 

 others. It is suggested that the collateral inquiry be carried out for the 

 determination of the best varieties of potatoes which enjoy a greater or 

 less immunity from attack. What it is, in the plant or tuber, that 

 causes this condition is not yet ascertained, and it is thought that possi- 

 bly when the cause is known the more sensitive varieties may be so 

 modified as to have an equal advantage. According to some the differ- 

 ence consists in the degree of smoothness of the external skin of the 

 potato, while others maintain that it depends upon the thickness of the 

 skin. 



