394 SUMMARY OF CURRENT RESEARCHES RELATING TO 



regards the mode of formation of the fruit. A new species, Melohesia 

 deformans, is described as parasitic on Corallina natalensis, in which, 

 instead of the usual regular pinnate structure of the apex of the 

 thallus, it branches in all directions into short irregular branches, 

 M. caUithamnioides produces peculiar gemmae, reminding one of those 

 of the Sphacelarieae. 



Impurities of Drinking Water caused by Veg-etable Growth * — 

 W. G. Farlow gives a resume of what is known respecting the vege- 

 table substances which cause impurities in drinking water. The 

 most injurious are the blue-green algae the Phycochromaceae, but 

 only after death. They do not, however, produce infectious diseases ; 

 Beggiatoa gives off sulphuretted hydrogen. The following are 

 described in detail : — Coelosphcernim Kutzingianum, Clathrocystis 

 ceniginosa, Anabcena flos-aqiice, and LyJighya Wollei. 



Fossil Siph.one3e.t — Meunier-Chalmas has determined the eocene 

 genus Ovulites to be identical with PeniciUus Link., Nesea Lmx., and 

 CoralHodendron Ktzg., from which he establishes a new section of 

 Siphonese, distinguished by their dichotomous branching. One of the 

 eocene species is closely allied to the existing Mediterranean CoralHo- 

 dendron mediterraneum. These were previously regarded as con- 

 stituting a class of Protozoa, under the name Dactyloporidese, to 

 which also belongs Triploporella, found by Steinmann in the calcareous 

 beds of the Lebanon. 



Falkenberg's Algse-X — In his new ' Handbook of Algae,' Falken- 

 berg follows in the main de Bary's classification § ; but introduces the 

 doubtful innovation of calling one of his four classes (including 

 Melanophyceae and Chlorophycefe) Algte in a restricted sense. The 

 author uses the term " gametes " for any masses of protoplasm, in 

 both Thallophytes and Archegoniatse, union of which constitutes a 

 reproductive act, including therefore oospheres and antherozoids ; the 

 result of this union, whether hitherto known as zygospore, oospore, 

 or fertilized ovum, he calls a " zygote." In the Floridese we have a 

 distinct mode of fertilization, viz. the impregnation of a multicellular 

 female organ, the " procarp," which developes into the fructification 

 containing the carpospores. The larger and smaller groups are 

 described with great clearness and an admirable selection of the 

 salient characters ; there is copious reference to the literature of each 

 section ; and the illustrations, though not very numerous, are excel- 

 lent, many of them being new. Unfortunately there is nothing in 

 the shape of an index. 



Motion of Diatoms. II — Mr. C. M. Vorce, while being unsatisfied 

 with any of the theories advanced and having none of his own, 



* Suppl. to First Ann. Rep. of Massachusetts Board of Health, 1880, 

 pp. 131-52 (2 pis.). 



t Bull. Soc. Geol. France, vii. (1881) pp. 661-70. See Bot. Centralbl., viii. 

 (1881) p. 270. 



X Falkenberg, P., ' Die Algen in weitesten Sinne,' Breslau, 1881 (Encyklo- 

 padie der Naturwissenschaften, lie Abtheil., 23 Lieferung). 



§ See this Journal, i. (1881) p. 273. 



[| Amer. Mon. Micr. Journ., iii. (1882) pp. 43-5. 



