872 EXPERIMENT STATION RECORD. 



the induction of lieliotropism become not only insensible to beliotropic 

 irritation, but also to geotropic, and that decapitation has the same 

 effect on geotropism of shoots as it has upon heliotropism. 



Experiments were conducted which showed that the loss of geotropic 

 curving is due to the loss in rapidity of growth and also the loss of 

 geotroi^ic sensitiveness. Experiments by the author show that the top 

 of the cotyledon possesses a very strong geotropic sensitiveness, and 

 that being concentrated at or near the top of the cotyledon it must be 

 admitted that the geotropic irritation is transmitted downward from 

 the top along the cotyledon. Otherwise the geotropic and heliotropic 

 curving would have been different instead of showing the same phe- 

 nomena. 



The author's conclusions are that decapitation of the cotyledons of 

 Graminew {Avena sativa, Phalaris cauariensis, Setaria viridis) causes 

 two effects independent of each other, namely, a strong retardation of 

 growth, and the loss of geotropic and heliotropic sensitiveness. If the 

 top is cut from plants where heliotropism and geotropism has been 

 induced in the shoots the curving is due to after action and they will not 

 respond to the new action of irritants. The elfects of decapitation last 

 but a few hours, after which the rapidity of growth as well as suscep- 

 tibility to irritants are gradually restored and at the end of 24 hours 

 become altogether normal. Experiments on Arena sativa show that the 

 previously unequal distribution of heliotropic sensitiveness is destroyed. 

 In experiments with shoots of Brassica napus decapitation produced 

 effects essentially the same so far as the principles involved are con- 

 cerned. 



Concerning copper from the standpoint of toxicology, A. 

 TscHiRCH {Bas Kiipfer vom Standpunkte der gerichtlichen Chemie, 

 ToxikoJogie und Hygiene; ahs. in Chetn. Ztg., 18 {1894) No. 102, Repert, 

 p. 329). — The author, contrary to the opinions of many others, says 

 that copper is not injurious to plants. The salts of copper, such as the 

 sulphate, chlorid, nitrate, etc., are corrosive and do exert an injurious 

 effect on plant life. Plants grown in soil that contained insoluble cop- 

 per compounds are said to have taken up some of this copper without 

 any injury. Water cultures of Fhaseolus multiflorus were grown in 

 nutrient solutions containing 2 gm. of copper oxid to every 3 liters of 

 the solution. The roots were thoroughly aerated from time to time and 

 no injury was apparent to the plants. Experiments were made with 

 36 culture plants under the above conditions and their growth was 

 stronger and the plants appeared more vigorous than parallel cultures 

 where the nutrient solution contained no copper. 



Synopsis of North American Amarantaceae, II, E. B. Uline and W. L. Bray 

 {Bot. Gaz., 20 {1895), Ko. 2, pp. 155-161). — A revision of the species of Aciiida and 

 Gomphrena is given. 



A revision of the genus Cordyceps, G. Massee {Ann. Bot., 9 {1895), No. 33, pp. 

 1-44, 2)ls. 2). — The author enumerates 62 species, one of which, C. velutipes, is de- 

 scribed as new. Of those fully described 22 species are peculiar to the Old World, 23 

 to the New World, and 6 are common to both. 



