744 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the genera described as parasitic among the Floridere are but incom- 

 pletely" known, especially as regards their biology, and the only two 

 genera which can rightly be named parasitic are the two above men- 

 tioned. Although the others show the strongly reduced thallus, which 

 is a character of parasitism, they either show definite rhodoplasts, or are 

 suspected of having such bodies. The following genera are therefore 

 to be regarded as half-parasites, Actinococcus Kiitz., Rirardia Derb. & 

 Sol., Melobesia Lamouroux ; while the parasitism of the following 

 genera remains doubtful : Gonimophyllum Batters, Janczewskia Solms- 

 Laubach, Colaconema Schmitz, Golacodasya Schmitz, Choreonema 

 Schmitz, Ceratocolax Rosenvinge, Syringocolax Reinsch, Sterrocojax 

 Schmitz, Episporium Mobius. All these genera need further investiga- 

 tion. The author deals fully with Choreocolax and Harveyella, and 

 finally discusses Gracilariophila, which he thinks is closely allied to 

 Choreocolax, and is certainly a true parasite. This is a newly described 

 genus parasitic on Gracilaria, and lately described by Setchell and 

 Wilson. Eddelbiittel's paper is a good summary of all that is known on 

 parasitic Floridese. 



Algas of Auckland and Chatham Islands.*— R. M. Laing gives 



an account of the algae collected during the ' Hinemoa ' expedition to 

 the islands lying south of New Zealand, namely, the Snares, and Auck- 

 land, Campbell, Antipodes, and Macquarie Islands. The list includes 

 eighty-nine species and two new varieties. Critical notes are appended 

 to many of the species. 



Fungi. 



(By A. Lobbain Smith, F.L.S.) 



Formation of Oogonia in Achlya.f— P. Obel worked with AcMya 

 decorata, a species which grows on sticks that have fallen into water 

 — mostly in forest bogs. It develops well on animal substrata (flies 

 and ant-eggs), or on vegetable (hemp-seeds), and, in these conditions, 

 produces oogonia rather than zoosporangia. In pure water, zoosporangia 

 were formed and very few oogonia. He tested the formation of the 

 different organs in varying media, and records the results. Potassium 

 phosphate furthers the formation of oogonia and of antheridia. The 

 want of phosphate induces the formation of parthenospores. It has 

 not been proved that these germinate. 



Study of Heterothallic Mucorini.J — Irene Korpatchewska found 

 that the different sexual thalli in the Mucorini, though morphologically 

 alike, reacted differently towards carbohydrates, certain substances being 

 absorbed more easily by the + form, others by the — form. When 

 the two forms were cultivated on the same substratum, sometimes one 

 and sometimes the other showed the more vigorous growth. These 

 physiological peculiarities were constant and were not modified by any 

 external influence. 



* Chilton, Subantarctic Islands of New Zealand. Wellington, N.Z., 1909, pp. 

 493-527 (4 pis.). f Ann. Mycol., viii. (1910) pp. 421-3 (4 figs.). 



t Bull. Soc. Bot. Geneve, ser. 2, i. (1909) pp. 317-32. See also Bot. Centralbl., 

 cxiv. (1910) pp. 192-3. 



