994 RECORD OF CURRENT RESEARCHES RELATING TO 



reducing, with the assistance of heat, Fehling's reagent. Since the 

 contents of the spermogonia of Gymnosporangium fusciim and conicum, 

 which contain the greatest quantity of this substance, have a strong 

 sweet taste, Eathay believes it to be sugar. 



The part of the host where the sugar-producing spermogonia of 

 the iEcidiomycetes are produced, is distinguished for a considerable 

 distance around. Thus, in the case of the ^cidiomycetes with mono- 

 carpous mycelium, the small part of the host which is possessed 

 by the mycelium, and on which the comparatively few spermogonia 

 make their appearance, is marked by a remarkably bright yellow, 

 orange, or red colour. And in the case of those with pleocarpons 

 mycelium, in which an entire branch of the host is infected, and the 

 spermogonia are numerous, breaking out either on all the organs of 

 the infected branch or only on the leaves, these infected branches are 

 doubly distinguished from the rest ; firstly, by their jieculiar appear- 

 ance, due either to the pale colour of their green parts, and the unusual 

 form of their leaves (like the shoots of Cirsium arvense attacked by 

 Puccinia ohtegens), or especially to their abnormally abundant branch- 

 ing and leafiness (like the " witch-broom " of the berberry caused by 

 JEcidium Magelhaenicum), or to the suppression of the flowers (like 

 the well-known sterile branches of Euphorbia cyparissias attacked by 

 Uromyces scutcllatus), and secondly by the sweet odour springing from 

 the spermogonia, as occurs in branches affected by Puccinia Anemones, 

 ohtegens, Falcarice, and Tragopogonis, Uromyces scutellatus, and ^cidium 

 Magelhaenicum. When the spermogonia have ceased to produce sugar, 

 their colour changes. 



In damp or stormy weather, the contents of the spermogonia 

 escape from their mouths in the form of small drops wbich adhere to 

 the paraphyses ; and these are eagerly sought for and consumed by 

 various insects, such as ants and some Coleoptera and Diptera which 

 are capable of taking up honey of this description, such as the honey- 

 dew formed by aphides, the nectar of extrafloral nectaries, the honey- 

 dew of ergot, &c. 



The author draws a comparison between the phenomena connected 

 with these male organs of the ^cidiomycetes, and the well-known 

 ones associated with the flowers of flowering plants. 



Infection of Puccinia Malvacearum.* — By experiments carried 

 on in the botanic garden at Giessen, Dr. Ihne confirms the previous 

 statements of Cornu and Kellermann that this fungus can be pro- 

 pagated by direct infection on leaves of the same plant as that from 

 which it was obtained, or of some other malvaceous species. The 

 only plant on which the parasite made its appearance this year at 

 Giessen was the hollyhock {Althaea rosea). From infected leaves it 

 was directly conveyed by artificial contact to others on hitherto sound 

 plants, and it spread also by spontaneous infection. Another plant 

 belonging to the natural order Malvaceae, Kitaihelia vitifolia, was also 

 infected in the same way ; but similar experiments on Lavatera 

 trimestris were unsuccessful. 



* 'Hedwigia,' xix. (1880) pp. 137-8. 



