1790 • FRUIT-GROWING 



with an air pump by means of tubes. Stopcocks regulate the suction in the 

 various tubes, and the temperatures in the differents parts of a stack are 

 registered by electro- thermometers. The object is to keep the temperature 

 constant at a pre-determined point, as if this cotild be maintained for a 

 certain time it would do away with the inconvenience of remaking the stack 

 when the tobacco heats too much, a process which greatly increases the 

 percentage of broken leaves. 



This plant has been improved during the last year and has given good 

 results with hands of tobacco placed in the middle of the stacks, while the 

 rise in temperature can now be checked at any desired point. Unfortunatel}'' 

 after the temperature has been lowered, the cooling process continues and 

 cannot be stopped. The hands placed towards the outside of the stack do 

 not derive any benefit from the aspiration of the air, and consequently 

 the stack must be remade for their benefit. It is hoped that better results 

 will be obtained by covering the stack with isolating material. 



A large thermostat has been devised for regulating the rise and fall 

 of temperature during fermentation, but the experiments so far have not 

 have not given any positive results. Special tests have shown that during 

 the first few days the lower layers of a stack heat up most, whereas later 

 on the hands placed in the middle of the stack reach a rather higher temper- 

 ature than those lower down. 



Other experiments have shown that if the stacks are made too large 

 and if moist tobacco is used they may overheat badly, resulting in serious 

 deterioration in the tobacco, even if the overheating does not cause the 

 stacks to catch fire. 



FRUIT 1291 - The Fruiting of Trees in Consecutive Seasons. — Pickering s., in journal of Agn- 



GROWiN'; cultural Science, Vol. VIII, Part I, pp. 131-135. Cambridge, September 1916. 



Points of considerable interest, both scientific and practical, are raised 

 by the question as to whether a tree which fruits exceptionally well as 

 compared with its fellows in one season, will tend to fruit exceptionally 

 well, or the reverse, in the following season. We know of no definite reason 

 why the behaviour of a tree as regards fruiting should alternate in consec- 

 utive years, and no such behaviour has been observed in the case of ani- 

 mals. Its doing so would imply that fruiting is due to the gradual accu- 

 mulation of some substance in the tree, which becomes exhausted whenever 

 heavy bearing occurs, and that the stock of this substance does not become 

 properly replenished till after another season has elapsed. 



The difficulties in obtaining exact measurements of the relative beha- 

 viour of any two or more trees in consecutive seasons are considerable. 

 The weight of fruit or the number of fruits may be recorded, but, unless 

 the trees are absolutely similar in size, disposition of branches, situation, 

 etc., which is impossible, the superiority of the one over the other as regards 

 inherent fruiting capabilities may be misleading. On the other hand the 

 trees under observation may be classified by inspection, grouping them 

 according to the extent which they are loaded with fruit, independent of 

 their size, and then comparing the classification in one 3'ear with that in 



