September 16, 1891.] 



Garden and Forest. 



443 



would cost about $3.50. It was not known how far the influ- 

 ence of this light would extend, but it was noteworthy that the 

 results were as well marked in the most remote parts of the 

 house as they were near the lamp. 



These results suggest many questions which can only be 

 answered by further trials. We need to know whether there 

 is any particular time in the life of the Lettuce-plant when elec- 

 tric light has a predominating influence ; whether a mild light 

 is as good as a strong one ; whether the failure of the light 

 during moonlight nights is a drawback ; to what distance the 

 influence of the light extends ; whether the same results can 

 be obtained by hanging a lamp over the house as inside of it, 

 so that several houses could be lighted at once ; and_ whether 

 any other plants can be profitably forced by electric light. 



Experiments with ornamental plants showed that the influ- 

 ence of light upon the productiveness and color of the flowers 

 varied with different species and different colors of the same 

 species, and that there is usually a perceptible gain in earliness 

 under the lamp, so that on the whole it seems possible that 

 electric light can be used to pecuniary advantage in floriculture. 



The second part of the bulletin gives an account of the ex- 

 periments tried elsewhere, commencing with some made by 

 Herve-Mangon thirty years ago, and including those of Dr. 

 Siemens, which have been published in the Proceedings of the 

 Royal Horticultural Society, and of Deherain's tests conducted 

 at the Exposition d'Electricite, which were published in the 

 Annates Agronomiques, vii., 551. 



In conclusion, it appears, from the many conflicting and in- 

 definite results so far obtained, that the problems to be solved 

 vary widely under different conditions and with different plants. 

 The points made clear are : The electric light promotes assimi- 

 lation, and often hastens growth and maturity ; is capable of 

 producing natural flavors and colors in fruits ; often intensi- 

 fies colors of flowers, and sometimes increases the production 

 of flowers. Since it is found that periods of darkness are not 

 necessary to the development of plants, there is every reason 

 to suppose that the electric light can profitably be used in 

 growing them. It will be necessary, however, to overcome 

 the injurious influences which this light exerts upon plants too 

 near it and the too rapid maturing of some species — in short, 

 a whole series of practical adjustments of conditions to indi- 

 vidual circumstances is required. So far, we have learned 

 more of the injurious effects of the light than of the beneficial 

 ones, but this means simply that we are learning definite facts 

 concerning the influence of the electric light upon vegetation, 

 and in some cases, especially in the Lettuce tests carried on at 

 Cornell, this has already been found a useful adjunct to a forc- 

 ing establishment. Professor Bailey concludes this highly 

 interesting and instructive bulletin as follows : 



"The experiments suggest many physiological speculations 

 upon which it is not the province of this bulletin to enter. 

 Yet two or three of them may be mentioned. It is a common 

 notion that plants need rest at night, but this is not true, in the 

 sense in which animals need rest. Plants have simply adapted 

 themselves to the conditions of alternating light and darkness, 

 and during the day they assimilate or make their food, and dur- 

 ing the night, when, perforce, assimilation must cease, they use 

 the food in growth. They simply practice an individual 

 division of labor. There is no inherent reason why plants 

 cannot grow in full light, and, in fact, it is well known that they 

 do grow then, although the greater part of growth is usually 

 performed at night. If light is continuous they simply grow 

 more or less continuously, as conditions require, as they do 

 in the long days of the arctic regions, or as our plants did un- 

 der continuous light. There is no such thing as a plant be- 

 coming worn out or tired out because of the stimulating influ- 

 ence of continuous light. 



" It would seem, therefore, that if the electric light enables 

 plants to assimilate during the night, and does not interfere 

 with growth, it must produce plants of great size and marked 

 precocity. But there are other conditions, not yet understood, 

 which must be studied. Our Radish-plants, and many others, 

 were earlier, but smaller, under the influence of the light. 

 Observation and chemical examination showed that a greater 

 degree of maturity had been attained. Perhaps they assimi- 

 lated too rapidly; perhaps the functions of the plant had been 

 completed before it had had time to make its accustomed 

 growth. Perhaps the highly refrangible and invisible rays 

 from the electric lamp have something to do with it. In fact, 

 this latter presumption probably accounts for much, if not all, 

 of the injury resulting from the use of the naked light, for the 

 effect of the interposition of a clear pane of glass is probably 

 to absorb or obstruct these rays of high refrangibility. Good 

 results which follow the use of a globe or a pane of glass show, 

 on the other hand, that the injury to plants cannot result from 



any gases arising from the lamp itself, as has been supposed 

 by some observers. In our own experiments, particularly 

 with the Brush lamp, there was no perceptible odor from the 

 gases of combustion ; and it may also be said that commer- 

 cial forcing-houses, like our own, are not tight enough to hold 

 sufficient quantities of these gases to injure plants. 



" It is highly probable that there are certain times in the life 

 of the plant when the electric light will prove to be particularly 

 helpful. Many experiments show that injury follows its use at 

 that critical time when the plantlet is losing its support from 

 the seed and is beginning to shift for itself, and other experi- 

 ments show that good results follow its later use. This latter 

 point appears to be contradicted by Deherain's results, but 

 his experiments were not conducted under the best normal 

 conditions. 



" On the whole, I am inclined toward Siemens' view, that 

 there is a future for electro-horticulture." 



Periodical Literature. 



The mid-August issue of the Revue Horticole describes the 

 interesting and important discovery of a French entomologist, 

 Monsieur Lemould, who has devised the means of destroying 

 the larvae of the Hanneton, the insect which in this country is 

 known as the May-bug or Dor-bug, and which for years has 

 done a serious injury to agriculture and horticulture in France 

 and in this country also. Monsieur Lemould has been study- 

 ing a cryptogamic plant parasite on the larvae of the Hanneton, 

 and has been experimenting with it at Ceauce', where he found 

 a field so infested with the white grubs, as these larvae are 

 usually called here, that the sod could be lifted with the hand. 

 About ten per cent, of the grubs was dead, their bodies being 

 covered with a white moss-like cryptogamic growth. The 

 dead were placed in contact with healthy grubs, and these at 

 the end of a couple of weeks had all contracted the disease. 

 Two months later the spread of the parasite had made enor- 

 mous progress, the affected grubs amounting to from sixty to 

 seventy per cent, of the whole number left alive in the field. 



On the 25th of last July Messrs. Prillieux and Delacroix com- 

 municated to the Academy of Science the result of their ex- 

 periments on the destruction of white grubs by the aid of 

 Botrytis tenella, a minute cryptogam, whose spores propagate 

 with prodigious rapidity, and which they had cultivated in the 

 following manner : A large crockery dish was set in a cool, 

 shady place and filled with a thin layer of moist sand. Upon 

 the sand were placed one hundred white grubs, and these were 

 covered with the spores of the plant reduced to powder. A 

 covering of damp moss was then placed over the grubs, and 

 the whole was covered with boards. In six or seven hours 

 the grubs were infected, and were then planted in an infested 

 field. The disease spread rapidly, and at the end of a few 

 months destroyed all the grubs, which died by myriads. 



The practical results of these experiments are assured, it 

 appears, and this new insecticide can be purchased from cer- 

 tain French chemists, who are prepared to deliver tubes filled 

 with it similar to tubes of vaccine. " We cannot foretell yet," 

 the editors of the Revue remark, "what results this discovery 

 will have for our agriculture or say that if its employment is 

 easy, practical and cheap, it will enable our agriculturists to 

 fight a pest which ravages whole regions, as was seen three 

 years ago in the departments of Mayenne and of Orne, but it 

 seems, at least, that it is capable of rendering immense ser- 

 vices to horticulture." 



The July number of Pharmaceutische Rundschau contains 

 an instructive article on the alleged poisonous properties of 

 the Wild Parsnip, that is, the common garden Parsnip, Pas-' 

 tiuaca"saliva, when it has run wild. It is stated in Dunglison's 

 Medical Dictionary that this is an irritant poison, and this is a 

 widespread popular belief. Dr. Frederick Power, however, 

 read a paper before the Wisconsin State Medical Society last 

 June, in which he gives the result of his investigation of 

 several cases of what was said to be poisoning by the Wild 

 Parsnip, which he had seen reported in the papers. In every 

 case where fatal effects occurred it was found that the root 

 eaten was not the Parsnip but Cicuta maculata, a plant which 

 belongs to the same family, and is known under the common 

 names of Spotted Cowbane, Musquash Root and Water Hem- 

 lock. So far as Dr. Power's investigations go, the wild Gar- 

 den Parsnip is not at all poisonous when taken, either in a 

 raw state or when cooked. Since this root of Cicuta is most 

 frequently taken for the wild Parsnip, and since such mis- 

 takes are often attended with fatal results, the distinguishing- 

 characters of the two roots are given. Cicuta maculata has 



