1012 EXPERIMENT STATION RECORD. 



to the pros(MK-o of an oxydizinj^- t'onrieiit or oxydas(\ The behavior 

 of ditferent kinds of latex in reference to oxyda.se.s i.s mentioned. As 

 a rule oxydases are more frequently found in innnature parts of plants. 



Investigations made of the car])ohydrates of latex show the presence 

 of sugar and stareh. The sugar is l)elieved to come from the surround- 

 ing tissues and not originally from the latieiferous tubes. Starch rods 

 were found abundantly in the ditierent parts of the plants, and, from 

 experiments conducted with dead and withered leaves, it is believed 

 that the starch ])resent in the latex has nothing direct!}- to do with 

 carl)on assimilation. Ditierent characteristics and properties are 

 noted in the latex of young and old organs of the same plant and of 

 difi'erent kinds.of plants. The eli'ectof previous wounding on the flow 

 of latex was investigated, and it was found that by repeated wound- 

 ings the amount collected could l)e increased as much as seven times. 

 This obser\iition was made with Hevea trees, and is of great practical 

 importance from an economic standpoint. In considering the origin 

 and function of latex, the author believes that its principal function 

 is in all probability as a reserve for water. The hypothesis that latex 

 is present in plants for protective purposes is, in the author s opinion, 

 hardly warranted, as rul)ber and other plants are su))ject to fungus 

 diseases and insect attacks to as great extent as manj" other plants not 

 provided with latieiferous tissues. 



The metabolism of proteids in plants, E. Schiilze(Z/.sy7//'. Phy.siol. 

 CIh',,1., JO [lOUU), \n. ■!-■'>. 2>i>. .>\l-.iU; Btr. Deut. Bot. (rr-sJl., J8 

 {1900), JS^o. 2, pp. S6-Jf!2). — A detailed report is given of a series of 

 experiments upon the metabolism of proteids ])y germinating seeds of 

 Plmiiii satlvuiiL, Vicia sativa., Luplniis latctis, and L. alhua., a prelimi- 

 nary account of the investigations having been given in the second pub- 

 lication noted above. In seeds germinated in darkness asparagin, 

 leucin, tyrosin, arginin, histidin, and 13'sin were found. The amounts 

 of these difi'erent substances varied with the seedlings, and with the 

 same seedlings at difi'erent times. An increase in asparagin was usually 

 accompanied b}' a decrease in the others, especially in the content of 

 leucin, tyrosin, and arginin. The proteid compounds which were 

 found to accumulate in the etiolated seedlings varied according to the 

 difi'erent kinds of seeds, arginin acumulating in L. luttui^^ while at other 

 times in old etiolated seedlings leucin was present in greater or less 

 degree. 



The previous theory of the author that the decomposition of proteids 

 in germinating plants results in the formation of ceilain amido acid 

 compounds as well as hexose bases through the action of acid or trypsin 

 within the organism is said to ])e confirmed. The varying amounts of 

 these compounds are attributed to the fact of their being secondar}' 

 products. The older hypothesis that the proteids in germinating seeds 

 split up into asparagin and carbohydrates the author claims is 

 untenable. 



