ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 583 



S. C. Stow * supplies a list of twenty-one diatoms collected at Clee 

 in March 1902. 



F. E. Burbury t gives a list of ninety-one species of diatoms found 

 in Tasmania, including Eunotia transylvanica, Hyalosira lohampoensis, 

 and Nitschia Clevei. 



Development of Tetrasporangium in Florideas-I — F. Heydrich 

 continues his observations on this subject and draws an analogy between 

 the development of the tetrasporangium and the fertilised carpogonium. 

 In the case of the carpogonium the sporogeuous euergid penetrates 

 into the auxiliary cell, and drives the nucleus of that cell into a remote 

 corner, where it perishes. As the result of this usurpation, the produc- 

 tion of carpospores becomes possible. 



Heydrich here describes a similar process in the tetrasporangium of 

 Polysiphonia variegata. Two cells are given off from a pericentral cell, 

 the lower one being designated the stalk-cell or karyoplastic-cell, the 

 upper one the protospore-cell. The karyoplastic-cell puts forth a small 

 tube towards the protospore-cell, and as soon as a connection is estab- 

 lished between them, the nucleus of the lower cell divides into two and 

 the upper one of the daughter nuclei passes into the protospore-cell. 

 The nucleus of the protospore-cell retires upwards and eventually 

 perishes, and the protospore-cell becomes the tetrasporangium mot'.ier- 

 cell. The analogy between the two processes is obvious. 



The author describes the development of the tetrasporangium in 

 Fauchea repens, Callithamnion, Ceramoihamnion, Hypnea, Dudresnaya, 

 and others. 



Structure and Development of the DesmarestifB.§ — Although so 

 much attention has been given to Desmarestia aculeata, there yet re- 

 mained certain points of interest in the genus to be worked out, and this 

 has been done by B. Jonsson. He has watched the different stages of 

 growth in D. aculeata and their duration, and gives an account of the 

 manner of development of the branches. The differentiation of the tissue 

 and the formation of secondary " central cylinders " is described, and 

 the functions of the various tissues are deduced from tlie cell-structure. 

 The other species of Desmarestia are dealt with shortly, the principal 

 work having been done on D. aculeata. 



The Rhodomelace8e.||— K. Falkenberg gives in this quarto book uf 

 svi. and 754 pages the results of many years of study on this group nf 

 Florideaj. It is published as one of the monographs of the Zoological 

 Station at Naples, and though the species found in that region are treated 

 with special detail, the work embraces the whole Order. The anatomical 

 development of the thallus, the morphology of the_ vegetative organs 

 and the reproductive organs are treated at length in a section of 1C9 

 pages. In the special part, consisting of 588 pages, detailed studies 

 of many species are given. Then follows ' Systematic Results,' dealing 



* The Naturalist, London, July 1902, p. 236. 

 t Papers and Proc. Roy. Soc. Tasmania, 1902, pp. 4-8. 

 I Bibliotheca BotamYa, Heft 57 (1902) pp. 1-9 (1 pi.). 

 § Kon-1. Fysio-iaf. Siillskap. Handling., Bd. 12, No. G, pp. 1-42 (3 pis.). 

 | Flora und Flora (ies GolfeB von Neapel. 26. Die Rhodomelaoeen. Berlin, 

 1901. xvi. and 754 pp., 24 pis. Sec also Amer. Naturalist, xxxvi. (1902). 



