NOTES ON RECENT RESEARCH. 



691 



and sub-families of the order. In regard to the function of the latici- 

 ferous elements, the author regards the latex as composed largely of 

 substances of high nutritive value, similar to, and in communication with, 

 reserve food-materials laid up in other parts of the plant. They also 

 communicate with the leaf-tissue, and are therefore regarded as a conduc- 

 tive system for substances elaborated in the leaves. A classification 

 based on the comparative anatomy and external features of the order is 

 given, and, on the whole, it agrees with the classification already in use. 



W. G. S. 



Starch in Evergreens. 



Evergreen Leaves, Starch Of, and its relation to Photosynthesis 

 during the Winter. By Kiichi Miyake (Bot. Gaz. xxxiii.,No. 5, p. 321). — 

 The experiments were conducted at Tokyo and elsewhere in winter. The 

 mean temperature of the three winter months is : Dec. 51° ; Jan. 2*7° ; 

 Feb. 3*5° ; that of London being 3'5° ; so that the coldest month (Jan.) 

 is colder than our metropolis. 



Of eighty species examined, seventeen were found to lose their starch 

 from the mesophyll during the winter. It was observed that the starch 

 contents of evergreen leaves are generally greater in April than in August 

 or September. 



The experiments sufficed to prove that many of the Evergreen plants 

 in Tokyo can form starch in the leaves by photosynthesis, and translocate 

 it to other parts of the plant-body during the winter. It generally begins 

 to decrease in November, the minimum being in January, and increases 

 again from the end of February. 



The quantity of starch is generally very little in winter compared 

 with that of other times of the year. It is formed by photosynthesis. 



The majority of evergreen leaves in the northern part of Japan nearly 

 lose the starch from the mesophyll and guard-cells in winter. — G. H. 



EUTYPELLA PRUNASTRI. 



Fungoid Disease of Nursery Stock. By G. Massee (Garel. 

 Chron. No. 822, p. 235, fig. 80 ; Sept. 27, 1902).— This disease, which 

 young Apple and Plum trees have suffered from lately in various 

 parts of England, is caused by a minute fungus, known as Euty pellet 

 pruneistri. It attacks the stem of the trees, and the first outward 

 indication of the disease is a slight browning of the bark, which soon 

 becomes hard, dry, and ins sparable from the wood. There is no crack- 

 ing or wrinkling of the bark, which presents a polished surface. The 

 mycelium continues to grow inwards, killing the young wood, and the 

 following season the leaf-buds either do not expand at all or only imper- 

 fectly, and during the summer the branches die through lack of food. 

 This fungus is by no means uncommon on Blackthorn, Bullace, Crab, 

 Wild Cherry, Wild Plum, &c. Infection sometimes takes place through 

 the punctures caused by insects, but more commonly by the fungus 

 germinating in the cut ends of twigs. Insects should be kept in check, 

 and it should be ascertained if the fungus be present on any of the wild 

 trees already mentioned. (Fig. 173.) — G. S. S. 



Y 2 



