278 SUiMMARY OF CUKKENT RESEARCHES RELATING TO 



only from the Atlantic or the Pacific, North and South, such an indication 

 may save time and trouble. A glossary of the terms employed renders 

 the key available for amateurs. E. S. Gr. 



New Pacific Coast Marine Algse. II., III., IV. — N. L. Gardner 

 {Univ. California Puhl. Bot, 1918, 6, 429-54, 455-86 ; 1919, 6, 

 487-96, pis. ;^)6-42). A continuation of the diagnoses and critical dis- 

 cussions of new Marine Algge from the Pacific Coast. In Part II. the 

 author presents thirteen new species of Myxophyceae which, with the 

 exception of two species of Chloroglma, belong to the group Chamsesi- 

 phonacese. Certain stages of development in Dermocarpa and Xenococcus 

 were found very troublesome to determine ; as also the genera Byella 

 and Radaisia, the limits of which have not been clearly defined. As 

 regards the latter problem, the author distinguishes them as follows : — 

 Those forms with erect filaments, more or less branched and distorted, 

 arising from basal filaments on the surface of the substratum and 

 growing into it, and having gonidangia at their bases near the surface 

 of the host, have been assigned to the genus Hyella. Those forms with 

 erect filaments, simple or complex, closely compact, more or less parallel, 

 not at all or only sliiihtly branched, arising in the same manner as those 

 mentioned above, but extending away from the host, and with goni- 

 dangia on the outer free ends, have been placed in the genus Radaisia. 

 In Part III. twenty-three species of Myxophyce^ are described and 

 discussed, of which twenty-one are new to science, while the remaining 

 two present alteration of nomenclature. In Part IV. five novelties are 

 described, belonging to Myxophyce^ and Chlorophycea;, and two species 

 are transferred from Urospora to Hormiscia for reasons given. In an 

 interesting discussion on his new species, Codium Setchellii, the author 

 gives his reasons for transferring thither all the hitherto recorded 

 6'. adhserens from the Pacific Coast of North America. With the excep- 

 tion of G. Setchellii, all the novelties appear under the joint authorship 

 of Setchell and Gardner. E. S. G. 



Alternation and Parthenogenesis in Padina. — J. J. Wolfe 

 {Jourii. Elisha Mitchell Sci. Soc, 34, 1918, 78-109. See also Bot. 

 Gazette, 67, 1919, 278). A study of the Dictyotaceous alga Padina 

 variegata found in North Carolina. The sperms, eggs and tetraspores 

 are borne on three distinct plants, which in the vegetative state are 

 quite alike, but are readily distinguishable in the reproductive phase. 

 Tetraspores give rise to sexual plants only, male and female, in nearly 

 equal numbers, so that sex appears to be predetermined during the 

 reduction division in the tetraspore mother-cell. Fertilized oospheres 

 give rise to tetrasporic plants. Thus there is an alternation of genera- 

 tions. Though unfertilized oospheres often germinate, yet these parthe- 

 nogenetic plants soon wither. A. G. 



Cytology and Life-history of Nemalion multifidum Ag. — Ralph 

 E. Cleland {Annals of Botany, 33, 1919, 323-51, 3 pis. and figs.). 

 An investigation of the red alga Nemalion, which produces no tetraspores. 

 The results are summarized as follows : — (1) Nemalion has a true 



