ABSTRACTS. 



735 



and is recorded from Shropshire, Yorkshire, Surrey, and Hants. It has 

 been most frequently met with on Picea cxcclsa, Link, but is also not 

 uncommon on Larix europcea, DC, and has recently been found in 

 Wiltshire on Finns excelsa, Wall. It is said also to occur either alone or 

 in company with D. calycina. 



In his summary, the author states : — " The Larch is most susceptible 

 to canker when quite young, and as the fungus spores in the majority of 

 instances gain an entrance to the living tissues through injuries caused 

 by the Larch aphis (Chermcs laricis, Hedwig), it follows that seedlings 

 and young trees should be protected against this pest. This can be 

 accomplished by spraying in the spring with paraffin emulsion, prepared 

 as follows : — Dissolve half a pound of soft soap in two gallons of hot 

 water, then add two gallons of paraffin, and mix thoroughly until the 

 ingredients do not separate on standing. One gallon of the emulsion 

 fehua prepared should be diluted with fourteen gallons of water, when it 

 is ready for use." 



" Recent investigations tend to show that the Spruce-gall aphis (Chermcs 

 abietis, L.) and the Larch aphis (Chermes laricis) are alternating stages 

 of one species. The sexual generation occurs only on the Spruce, the 

 agamic generations, consisting entirely of females, then migrating to the 

 Larch. Under the circumstances, a mixture of Spruce and Larch is not 

 to be recommended, as it furnishes the aphis with its two necessary host- 

 plants. 



" As a safeguard against inoculation taking place through bark fissures 

 caused by late frosts, it is advisable not to form seed-beds nor to plant 

 Larch in low-lying, damp localities, where not only are the plants most 

 exposed to frost, but such situations also favour the presence of aphis. 



" In the case of larger trees there is no cure. If the trunk is not 

 seriously injured the tree may continue to grow and make wood for many 

 years after being cankered. However, it is very important to remember 

 that the toleration of canker-bearing ascophores is a serious menace to 

 surrounding trees. As the spore is the only known means of transmitting 

 the disease from one tree to another in a state of nature, therefore, when 

 ever practicable, all canker wounds should be cut away, and the removed 

 portions burnt. Protect the cut surface with a coating of gas-tar." 



The author also gives details of his experiments with the fungi, and 

 the work is embellished with beautiful coloured and plain figures 

 representing the disease in its various phases. — B. N. 



Cantaloupe Blight. By H. H. Griffin (U.S.A. Exp. Stn. Colorado, 

 Press Bull. No. 4 ; June 1900). — A fungus, Macrosporium cucumerium, 

 Ellis & Everh, attacks the leaves of Cantaloupes, causing a number of 

 brown spots to appear on the leaves ; these spread until the whole leaf is 

 destroyed. The result of the attack is to cause the fruit to ripen pre- 

 maturely and to become insipid. Spraying with Bordeaux mixture (6 lbs. 

 copper sulphate, 4 lbs. fresh lime, 40 galls, water), and ammonia cal 

 copper carbonate were both tried, and the Bordeaux mixture was found to 

 be most satisfactory. The spray checked the progress of the disease and, 

 by prolonging the life of the plant, enabled the fruit to develop properly. 



F. J. C. 



