228 EXPERIMENT STATION EECORD. , 



The removal of the taproot, severe priming, removal of portions of the crown, 

 and cutting back of the vines failed to cause any change in the normal pro- 

 duction of the flowers. The experiments further showed that plants would 

 transmit the abnormal type of inflorescence when propagated asexually, and 

 that only plants bearing pistillate flowers are subject to a reversal of the sex. 



In an experimental plat of 1,400 seedlings all the plants were apparently 

 normal at first, but later in the summer some of the iilants bearing pistillate 

 flowers developed staminate ones also. None of these plants had been sub- 

 jected to any severe treatment and it is held that some factor other than 

 traumatism must produce sex reversal. 



Corallorhiza and mycosymbiosis, B. C. Gruenberg (Abs. in Science, n. ser., 

 31 (1910), Ao. 7.99, j). 633). — ^An examination of the rhizomes of several species 

 of Corallorhiza showed that they contained secondary starch, which the author 

 claims must have been derived from organic materials in the soil or humus. 

 In considering the fungus symbiont it is not thought that the Corallorhiza 

 is dependent upon it for its nutrition. While the sj-mbiosis is a constant char- 

 i\cter of the species examined it is thought to be a result of the habit of the 

 fungus and not to be obligatory for the maintenance of the orchid. It is 

 thought that the fungus may assist the orchid by furnishing conditions favor- 

 able to the germination of the seeds, but it is believed that other conditions 

 may also stimulate the seeds to germinate. The infection of the rhizome is 

 said to take place about the time of germination. The digestion of hyphal 

 masses within the cortical cells is considered as a means for preventing the 

 spread of the fungus to the point of injuring the orchid and is not assumed to 

 be necessary for the nutrition of the plant. 



Studies upon oxidases, H. Hasselbring and C. L. Alsberg (Abs. in Science, 

 n. ser., 31 (1910), No. 799, p. 637). — In investigations of a disease of cabbages 

 and spinach resembling in some respects the mosaic disease of tobacco, the 

 authors found that there appeared to be an increase in the oxidizing power of 

 the plants. Studies of the extract of the plants showed that there was probably 

 not an increase in the oxidase but a decrease in the anti-oxidases. It has 

 been shown that heating plant extracts would cause a loss of the oxidizing 

 power, which would be restored after the solution had stood for several hours. 

 In the authors' investigations it was found that if a heated extract was 

 centrifugated immediately after heating and the clear liquid pipetted off from 

 the coagulum, the clear liquid did not acquire any oxidizing power on standing, 

 while the liquid containing the coagulum did recover it. It is believed that in 

 this case the authors were dealing not with a zymogen but with the inclusion 

 of the enzym in the clot and its subsequent leaching out on standing. 



The protection of plant cells against fungus attack, L. P. Brullov (Zhur. 

 Bolyezni Rast., 1908, No. 1; abs. in Zhur. Opuitn. Agron. (Russ. Jour. Expt. 

 Landiv.), 10 (1909), No. It, pp. 591, 592). — The results of laboratory investiga- 

 tions on the protection of plants against fungus attack are given. 



The studies were made with laboratory material of Vaucheria sessilis (?), 

 which the author states is a good subject for study on account of the ease 

 with which it may be examined. It is quite frequently attacked in the labora- 

 tory by an undetermined fungus, the hypha of the fungus attaching itself to 

 the cell wall of the host plant. In response to the irritation caused by the 

 fungus the protoplasm of the cell deposits on the inner side of the cell wall a 

 series of layers to protect against the entrance of the fungus. As a result 

 of these deposits the fungus either ceases to grow, or, if it is very active, ulti- 

 mately penetrates the protecting layer and expands within the cell, destroying 

 its contents. The cellulose deposit, on account of its resistance to staining 

 reagents, is said to be readily observed and seems to be a form of suberin or 



