396 General Notes. [April, 
sang (Niederrhein. Gesell. fiir Natur-und Heilkunde, 1862). A 
similar diorite has been mentioned by Reinhold? as occurring in 
Placer county, Cal. (vid. NATURALIST, 1882, p. 610). Michel- 
Lévy? has established seven different types of volcanic rock occur- 
ring in and near Mont Dore, in Central France. They include 
domite, cinerite, trachyte, andesite, phonolite and basalt. 
BOTANY. ° 
HYBRIDIZATION oF Porators.—During the past year some ex- 
periments were made at Reading, England, upon the grounds 
of Messrs. Sutton & Sons, the eminent potato growers. Un- 
der the advice of Mr. J. G. Baker the attempt was made to 
secure a hybrid between the common potato and the Darwin 
potato (Solanum maglia) from the southern part of South Amer- 
ica. The experiment is reported as having been successful, and 
we may look ere long for the tubers of this new form. “ Every 
gardener and farmer may now welcome the birth, so to speak, of 
a hybrid which we may hope will enable the potato plant to resist 
the attack of parasites, and especially of those of the devastating 
fungus, Peronospora infestans.” 
HETEROECISM OF CEDAR APPLES.—Dr. Farlow has been study- — 
í: 
1. The æcidium of Gymnosporangium biseptatum is probably 
Restelia botryapites [on Amelanchier]. 
“2. The æcidium of G, globvsum (to be kept distinct from G. 
Juscum) is possibly Restelia aurantiaca [on Crategus oxycantha]. 
“3. The ecidium of G. macropus is to be sought among the 
Reesteliz growing especially on apples and Amelanchier.” 
NortH American Forests.—The North American continent, 
ae 1 Proc. Philad. Acad. Nat. Science, 1882, p- 59. 
: _ * Comptes Rendus, T. XCVIII, 1884, p, 1394. 
= 3 Edited by Pror. C. E. Bessey, Lincoln, Nebraska. 
