SERICULTURE 1643 



1201 - Ontario Beekeepers Association Honey Crop Report for 1916 in The Canadian 



Horticulturist and Beekeeper, Vol. 24, N°. 9, p. 225. Peterboro, Ont. September 1916. 

 The White Honey Crop in 50 counties of Ontario, in 1916, according 

 to the Ontario Beekeepers' Association, was 2127903 pounds, from 23 763 

 colonies (spring count) with an average of 89,6 pounds per colony. The 

 honey crop in 1915 was i 175 871 pounds from 20 402 colonies. 



1202 -The Work of the Institute for Research on Silkworms atPortici (Italy). — acqua 



C, Rendiconti delF Instituio bacologico delta R. Scitola siiperiore di Agricoltura in Portici, 

 Vol. I, pp. 1-98. Portici, 1916. 



I. Experiments on the digestion of silkworms. — In order to investigate 

 the digestibility of proteins, fats and carbohydrates by silkworms a quant- 

 ity of intestinal juice was extracted from worms under normal conditions 

 of rearing and its effect on the various substances was studied in vitro. 

 The presence of an active protease was proved. This ferment works in an 

 alcaline medium and must be considered of the nature of a trypsin, acting 

 on blood fibrin and on egg albumen either in the liquid or coagulated form. 

 Starch and fats were untouched and this was confirmed by microchemical 

 tests carried out on pieces of ingested mulberry leaf which were removed 

 from various parts of the intestinal tract. On the other hand, as soluble 

 sugars which are contained in considerable quantities by the leaf were di- 

 gested, the starch in the leaf must be absorbed indirectly. The cell mem- 

 branes of ingested leaves remained absolutely unaltered, so that absorption 

 of protein substances from the cytoplasm could only take place after the 

 rupture of the cell walls. With regard to the chlorophyll, it would seem 

 certain that where the tissue was disintegrated the pigment contained in the 

 chloroleucites was absorbed, but where the chloroleucites remained enclosed 

 inside the cells, the pigment remained unaltered. This fact was confirmed 

 by a spectroscopic test. The secretions from the anterior and middle por- 

 tions of the intestine were precisely similar in their effect, but the secretion 

 from the posterior part of the intestinal tract was absolutely inactive. 



II. Phototaxy in silkworms (i). 



III. Experiments on the absorption of glucose by stems and leaves of mul- 

 berry trees. — In a previous paper (2) a description has already been given of 

 the methods adopted for obtaining the absorption of liquids by the aerial 

 parts of plants. It consists in cutting through the petioles near the blade 

 of the leaf or cutting the tips of young shoots and placing the cut surfaces 

 in the solution to be tried. The method was applied to Morns alba, using 

 a solution of 5 per cent glucose for the cut ends of young shoots or a solution 

 of 6 to 10 per cent applied in a glass tube to a wound made in the trunk 

 of the tree. Where the experimental plants were ver}^ young, the glucose 

 absorbed had a very marked effect : growth was increased ; the shoots were 

 longer and thinner and much less rigid so that they required support ; the 

 leaves were larger and thinner showing a considerable reduction of the pal- 

 issade and spongy tissues. With the medium-sized plants the growth was 



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(i) See R. March 1916, No. 328. {Ed.) 



(2) Rendiconti delV Accadcmia dci l.incei, Vol. XXIII, 191 3. 



