246 EXPERIMENT STATION EECOED. [Tol. 37 



regions not previously known to contain totipotent cells such as supposedly 

 originate tumors on inoculation in the neighborhood of dormant buds, tumors 

 are produced too numerously to be explained as due to the development of em- 

 bryonic " cell rests " or what are conceived to be fragments displaced from 

 the embryo in early stages of growth and remaining dormant amid other tis- 

 sues. It is claimed that embryomas are the results of specific tissue responses 

 to the stimulus of a specific schizomycete, taking the embryoma form if a com- 

 plex anlage containing totipotent or nearly totipotent cells is Involved. The 

 conclusion is regarded as almost unavoidable that cancer is due to a parasite 

 and that, as shown in case of plants, this parasite may be found to give rise 

 to the most diverse forms of the abnormality. 



Report of the pathologist, J. A. StevExNSON {lipt. Bd. Comrs. Agr. P. R., 5 

 {1015-16), pp. SS-lJf). — In addition to an account of routine work of the 

 laboratory, the author gives de.scriptions of citrus and sugar cane diseases 

 observed in Porto Rico. Notes are also given on a number of minor diseases, 

 among them root knot of various ornamental and other plants, trunk rot of 

 Ficus nitida due to Nummularia bulliardii, a root rot of avocado caused by 

 an undetermined fungus probably of the Nummularia group, together with 

 notes on entomogenous fungi. 



[Reports on botany and plant diseases in Switzerland, 1913-14], H. Mui.- 

 ler-Thuegau et al. {Landw. Jahrb. Schicciz, 29 {1915), No. 5. pp. 476-484. 

 50S-522, 574, 575, 57S, 579, 593, 594).— The sections hero noted relate to obser- 

 vations and experiments in connection with various phases of botany and plant 

 parasitism, including disease resistance and injury by nematodes as well as by 

 other animal pests. 



Notes are given on a number of rather common parasites observed on various 

 economic plants, the information being grouped according to whether the liosts 

 are orchard, garden, or ornamental plants. There are also brief accounts of 

 special studies on sugar in floral leaves; acetaldehyde formation in orchard 

 fruits; hydrofluoric acid Injury to grapes; cases of Phytophthora disea.se; con- 

 trol of Pseudopcziza trachciphila on grapevines; Guomonla on cherry leaves; 

 control of Oidium euonymi japoniccr ; a dieback of young plum trees probably 

 due to root fungi; injury to ornamental plants by Aphelenchus onnerodis and 

 Tylenchus dipsaci; and control of grape Peronospora, leaf roll of grape, and 

 SpficBrella fragaricB on strawberry. 



Fungus parasites of the higher plants in the region of Kharkov and ad- 

 jacent provinces, A. A. Potehma {Kharkov. Obhmt. Sclsk. Khoz. Opytn. Sta., 

 Fitopatol. Otd., No. 1 {1916), pp. 121-251, figs. 21).— In continuation of a pre- 

 vious report (E. S. R., 35, p. 453) an account is given of the a.scomycetous para- 

 sites up to and including In part the Erysiphaceae. 



Of the ExoasceiE, species of Taphrina (in which the author includes the mem- 

 bers of Exoascus) are found on a large number of hosts In four different fami- 

 lies. Among Discomycetes, species of Sclerotinia and Pseudopezlza appear to 

 be most prevalent. Particular attention is called to the occurrence of a little- 

 known parasite, Phacidiella discolor, found on pear, apple, and Pynis para- 

 disiaca. This fungus causes serious trouble, however, only in case of apple, 

 killing the bark on the trees and thus producing large wounds. 



Diseases and pests of cultivated plants in the Dutch East Indies in 1915, 

 C. J. J. VAN Haxl {Dept. Landh., Niji\ en Handel [Dutch East Indies], Meded. 

 Lab. Plantcnziekten, No. 20 {1916), pp. 47). — An account Is given of diseases 

 and animal enemies affecting a large number of orchard, garden, forest, and 

 field plants in Java during the year, with control measures employed or recom- 

 mended, together with a list of phytopathological literature which appeared 

 in 1915 relating to the Dutch East Indies. 



