ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
665 
section of Cryptogams. He maintains that tbe relationship of the fungus 
to the alga is one of true parasitism rather than of symbiosis. Though 
ihe alga is not killed, it is undoubtedly injured by the parasitic fungus. 
The soredes are not found in all lichens, and may be compared to 
gemmae ( Brutzellen ). It is probable that representatives of various 
families of Fungi have acquired the habit of carrying on a parasitic life 
on Algae. 
Pigments of Lichens. — Prof. W. Zopf * * * § has extracted the following 
crystallisable substances from various Lichens : — Pinastrinic acid from 
species of Cetraria ; solorinic acid C 15 H 14 0 5 from Solorina crocea ; 
rhizocarpic acid from Rhizocarpon geographicum ; pleopsidic acid from 
Pleopsidium cliloroplianum ; vulpinic acid from Calycinum chlorinum ; 
sethyl-pulvinic acid from Physcia medians and P. Callopisma ; calycin from 
various lichens ; psoromic acid, &c. from Rhizocarpon geographicum ; 
zeorin from Physcia csesia and P. endococcina. 
Herr O. Hesse j* finds in Usnea harbata a usninic acid C 18 H 16 0, and 
barbatin C 9 H 14 0 ; also, in various varieties, carbonusninic acid C 19 H 16 0 8 . 
Parmelia perlata yields small quantities of vulpinic acid ; from Clado- 
nia coccifera cocellic acid C 20 H 22 O 7 was obtained ; from Cetraria 
Juniperina var. Pinastri , a substance identical with pinastrinic acid ; 
from Parmelia parietina , a substance previously named physciacic acid 
and chrysophyscin, which the author now determines to be a chinon 
with the composition C 15 H 9 0 4 (0CH 3 ), and names physcion. 
Minks’s Microgonids.J — Herr 0. Y. Darbishire enters into a detailed 
criticism of Minks’s claim to have discovered organs in Lichens to which 
he gives the name microgonids. These observations rest, according to 
the author, on erroneous interpretations, largely due to the fact that 
Minks made his observations not on Lichens in the living state, but on 
preparations which had been subjected to the action of various reagents. 
From observations made chiefly on Leptogium saturninum in the living 
condition, Darbishire comes to the conclusion that the so-called micro- 
gonids observed within the gonids are probably identical with the small 
granules detected by Bornet and Flahault in the cells of the hetero- 
cystous Nostocaceae. 
Uredinese with Repeated Formation of iEcidia.§ — According to 
Dr. P. Dietel, those Uredineas which produce aecidia and teleutospores, 
but no uredospores, can form aecidia directly from the germination 
of aecidiospores without the intervention of an alternate generation. 
This was proved experimentally with Puccinia Senecionis , Uromyces 
Belienis , U. Ervi, and U. Scrophularise. These species either produce 
no spermogones, or the formation of spermogones precedes the first 
^ecidial generation, and is suppressed in the following ones. 
Entomogenous Fungi. |] — Mr. B. H, Pettit gives the results of a 
series of experiments on inoculating noxious insects with entomogenous 
* Ann. d. Cliemie,cclxxxiv. pp. 107-32. See Bot. Centralbl., lxiii. (1895) p. 174. 
Of. this Journal, 1893, p. 496. 
t Tom. cit., pp. 157-91. See Bot. Centralbl., lxiii. (1895) p. 177. 
X Hedwigia, xxxiv. (1895) pp. 181-90. Cf. this Journal, 1879, p. 311. 
§ SB. Vers. Deutsch. Naturf. u Aerzte, 1894. See Bot. Centralbl., lx. (1894) p. 161. 
|| Cornell Univ. Agric. Exp. Stat., Bull. No. 97, 1895, 39 pp. and 11 pis. 
