130 THE VICTORIAN NATURALIST. 



wall of the tube was shown to be made up of three layers — 

 ectoderm, mesoderm, and endoderm — the structure and function 

 of the " collared " cells constituting the endoderm being specially 

 dwelt upon. The examples cited as affording good examples of 

 this group were Leucosolenia lucasi and L. stolonifer — forms 

 obtained recently near Port Phillip Heads by Mr. J. B. Wilson, 

 M.A., and described, together with other members of the group, 

 by Dr. Dendy, in the " Transactions of the Royal Society of 

 Victoria," vol. iii.., part i. 



In the case of the Heteroccela, it was shown that the simple 

 canal system of the Olynthus type is considerably modified, and 

 there is a series of tubes or thimble-like chambers radiating from 

 the gastral cavity, each chamber being lined by a layer of 

 " collared " cells. In some forms, such as Sycon raphanus and 

 Sycon carteri, these radial tubes or chambers project freely 

 towards the exterior, so that the sponge externally has 

 the appearance of a pine-apple ; but in such a form as 

 Sycon gelatinosum the chambers are enclosed in a common 

 cortex, which extends from chamber to chamber. Still 

 further modification as regards the arrangement of the 

 chambers was shown in the case of Leucandra phillipensis and 

 Vosmaeropsis mascera, where they are round or oval in shape, and 

 are scattered irregularly throughout the mesodermal tissue lying 

 between the external cortex and the central gastral tube. 

 Reference to the arrangement of the skeleton, the histological 

 elements and development of sponges brought an extremely 

 interesting and instructive address to a close, and a vote of 

 thanks was unanimously accorded Dr. Dendy for the trouble he 

 had taken to make the evening a success. 



A series of preparations for the microscope, designed to 

 illustrate some of the facts set forth in the lecture, was distributed 

 to those who had microscopes, and included mounted specimens of 

 Sycon raphanus, a spread of calcareous spicules, and stained 

 sections of Sycon carteri, and Sycon gelatinosum. Little time 

 remained, however, for examination of these preparations, so it is 

 proposed to devote another evening, at a future date, to this 

 special work, when a few additional typical sections will be 

 described and distributed, that the series may be somewhat more 

 complete. 



THE EDITOR OF THE "VICTORIAN NATURALIST." 



The Chairman then announced that Mr. A. H. S. Lucas, M.A., 

 B.Sc, who has edited the Victorian Naturalist since its inception 

 nearly nine years ago, had tendered his resignation as editor, 

 owing to his election to the head-mastership of Newington College, 

 Sydney. Testimony was borne to the great services Mr. Lucas 

 had rendered to the Club in this department ; and, on the pro- 

 position of Professor Spencer, seconded by Mr. H. T. Tisdall, 



