86 NATURAL SCIENCE [August 



tion which, as Messrs Ikeno and Hirase point out, Hofmeister had 

 suggested would be forthcoming. It is of much interest that 

 Conifers represented by Gingho, 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 Gingho, 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 



It 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 186 4. Now, however, the Russian botanists 

 Woronin and Nawaschin (Zeitschr. fur Pflanzcnkrankcnheiten, 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 Sclcrotinia 

 Jteteroica. The resting-stage (or Sclerotium) giving rise to the 

 Ecziza-iorm grows in the capsules of Ledum palustve ; 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 



