678 SUMMARY OF CURRENT RESEARCHES RELATING TO 



point deals with the effect of outside influences on the growth of the 

 plant and the distribution of its spores. The round sporangia are said 

 by Karsten to flourish most in damp surroundings and the hooked 

 sporangia to prefer the air, and this author finds that species bearing 

 round sporangia grow more constantly on vertical surfaces, those with 

 hooked or funnel-shaped sporangia preferring a horizontal surface. He 

 adds that further study on these points is to be desired. 



Under Polymorphism the author deals with the changes in form 

 brought about in the same species by varying conditions, and deprecates 

 the view that a change in the outward form of the sporangia indicates 

 a transition from one species to another. His method of preparation 

 in examining dried material is given and the effect of various reagents 

 on the specimens. 



Two new species are described, T. Negeri from Chile and T.annulata 

 from Bavaria ; and a new form punctata of T. aurea Mart., found near 

 Partenkirchen in Bavaria. A list of literature on the subject is given. 



Chondrus crispus. * — Otto V. Darbishire publishes a detailed 

 account of this alga, containing all that had been previously known 

 about it, together with the results of his own observations. In the 

 Introduction, methods of collecting algae are described, and instructions 

 are given concerning their preparation for the herbarium and the Micro- 

 scope. Then follows a section devoted to the external morphology, 

 anatomy, and histology of the vegetative organs, physiology of the 

 vegetative organs, the reproductive organs, and ecology. Concluding 

 remarks contain a full diagnosis of the plant. The author succeeded in 

 germinating tetraspores of C. crispus on small strips of parchment 

 paper, which were first soaked in running water in order to remove any 

 acid present. These strips were laid at the bottom of small glass 

 troughs, filled with fresh filtered sea-water, and kept cool in a fairly dark 

 place. On these strips was placed a fresh plant bearing a nemathecium. 

 The tetraspores escaped on to the parchment, and it was then possible 

 to observe (he stages of germination by placing the parchment, with 

 certain precautions, under the Microscope. 



In the section headed Ecology the author gives the results of his in- 

 vestigations as to the vertical distribution of certain species of marine 

 algae in Port Erin Bay. 



The Genus Halimeda.t — Ethel S. Barton gives here a structural 

 and systematic account of this genus. It is shown that the manner of 

 communication between the filaments of the central strand of the thallus 

 forms a good specific distinction, and the author is thus enabled to 

 reduce the number of species from twenty-one to seven. Certain of the 

 former species represent types of variation within the limits of one 

 srecies. Communication takes place between the filaments of the central 

 strand when these reach the apex of a joint or internode ; this com- 

 munication may take place either by means of large open pits in the 

 walls, or the filaments may fuse in twos or threes. In order to ascertain 

 the manner of communication it is necessary to decalcify the apex of a 



* Liverpool Mar. Biol. Committee Memoirs, ix. (1902) pp. viii. and 42 (7 pis.). 

 t Siboga Expeditie, Monogr. lx. (Leiden, 1901) 32 pp. (4 pis.). 



