564 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
ganic, have a distinct influence on their growth. An increased activity 
of growth of the mycele is, however, frequently accompanied by a 
retardation in the production of conids. The colour of the conids is 
sensibly affected by the chemical composition of the nutrient medium. 
Pleomorphism of Fungi. * — In reviewing the question of pleo- 
morphism, Dr. 0. Jolian-Olsen follows the lead of Brefeld, who laid down 
the proposition that parasitism is to be regarded as an adaptation 
phenomenon ; and the author’s view is that, as a rule, the primary form of 
a fungus lives on dead matter, is a saprophyte in fact, and that if there be 
a parasitic form, this cannot exist for ever as a parasite, but must return 
to the saprophytic condition in order to regain the power of invading 
living tissue. A large number of examples of the variations of fungi 
under natural and artificial conditions are referred to, and these certainly 
lend colour to the view that so little is known as yet about these fungi 
that it would be wise not to dogmatise too strongly. Hence it would be 
better to regard most bacteria as adaptation forms, and not as independent 
species, and, after Coppen Jones, speak of Tuber culomyces just as we do of 
Actinomyces. 
Classification of the Spores of Fungi. | — M. P. A. Dangeard suggests 
a classification of the spores of Fungi, from the point of view of their 
origin, different from any of those which now prevail. Conids (e.g. 
Penicillium crustaceum ) he defines as spores which are derived from the 
continued division of the single nucleus of a mother-cell. These conids 
may, however, be of two kinds : — (1) they are the result of the budding of 
the mother-cell (. Aspergillus , Trichoderma lignorum , and many Mucedineae, 
spermogones of Uredineae, Saccharomyces'), and this is the most common 
mode of production ; (2) they result from the division of the mother-cell 
( Sphserotheca Castagnei). The conid is, in its origin and structure, a 
nonsexual spore in every sense of the term. In the Coremium-st&ge of 
Penicillium the spores are not produced from a mother-cell, but by the 
breaking up into cells of multinucleated fertile branches, as in Oidium 
lactis ; and for this kind he proposes the term oidia ; they are not 
necessarily the result of the division of a nucleus. Chlamydospores are 
encysted oidia. The Ascomycetes and the Basidiomycetes produce both 
conids and oidia. Uredospores and aecidiospores must be regarded as 
conids. Both conids and oidia may be compound. Conids are altogether 
analogous to the spores of the Muscineae and Filices ; while oidia have 
more analogy to bulbs, gemmae, and similar structures. 
New Genera of Fungi. — In a collection of Fungi from South 
America, Herr P. Hennings J finds a number of new species, and the 
following new genera : — 
Ditella (Uredineae). Sporae continuae, catenulatae, sine cellulis inter- 
stitialibus, pseudoperidio tectae ; sori subtremelloidei, subglobosi, basi 
immersi. D. verruciformis , on leaves of Sida macrodon. 
Hypocreodendron (Hypocreaceae). Stroma carnosum, truncatum, 
fruticiformite ramosum ; perithecia stromatis parte superiori disciformi 
tantum immersa, subglobosa ; asci baud conspicui ; basidia ramosa ; 
* Centralbl. Bakt. u. Par., 2 te Abb, iii. (1897) pp. 273-84 (1 ph). 
t Le Botaniste (Dangeard), v. (1897) pp. 313-7. 
j Hedwigia, xxxvi. (1897) pp. 190-246 (1 pi.). 
