86 NATURAL SCIENCE [August 
tion which, as Messrs [keno and Hirase point out, Hofmeister had 
suggested would be forthcoming. It is of much interest that 
Conifers represented by Gingko, as well as Cycads, show this rela- 
tion ; as we have always been wont to consider the latter so much 
the more ancient group both on palaeontological and morphological 
grounds. And Gingko, the maiden-hair tree, which with its strange 
fern-like foliage and non-conelike inflorescence, has always attracted 
us, will become still more fascinating. The confirmation of the news 
to which we have referred was supplied by Dr Scott, who at the last 
meeting of the Linnean Society showed actual microscopic prepara- 
tions which he had received from Japan. A few more details will 
be found in a note communicated by the discoverers to the June 
number of the Annals of Botany. 
FUNGI AND THEIR Hosts 
Ir is generally understood that a fungus, when parasitic, preys upon 
one and the same host during the whole period of its life-history. 
Hitherto only a single exception to this rule has been recorded, 
namely, that of certain ‘rusts’ (Uredineae), whose heteroecism (as 
change of host is technically termed) was first demonstrated satis- 
factorily by De Bary in 1864. Now, however, the Russian botanists 
Woronin and Nawaschin (Zeitschr. fiir Pflanzenkrankenheiten, vol. 
vi., 1896, pp. 129, 199) have discovered an interesting case of 
the same exceptional phenomenon, namely, in a new species of the 
Ascomycetes which they have described and named Selerotinia 
heteroica. The resting-stage (or Sclerotium) giving rise to the 
Pezxiza-form grows in the capsules of Ledum palustre; the other 
(or conidial) form they found as a destructive parasite on the leaves 
of Vaccinium uliginosum. The fruit of Ledum palustre is attacked 
at an early stage of its growth, and is gradually replaced by the 
sclerotium. The diseased capsules, which do not differ much in 
appearance from the healthy fruits, remain attached: to the parent 
plant during the winter, and fall to the ground in spring’ when 
the stalked cup-shaped ascus-fruits are developed. The ascus 
spores, scattered by the wind, light on the buds and young leaves of 
Vaccinium, where they germinate and spread through the cells of 
the plant. The conidial fructification, upright stalks with branched 
chains of conidia, appear on the petiole and veins of the leaves, 
which turn brown and gradually die. The authors by repeated ex- 
periments established without doubt the relation between the two 
forms ; but it is rather remarkable that they were able to cultivate 
the conidial form from the ascus spores on a decoction of plums ; 
and this fact, as pointed out by Fischer, interferes between the 
parallel with the above case and that of the Uredineae. The 
