28-4 SUMMARY OF CURRENT RESEARCHES RELATING TO 



adapted itself fairly early to ecological conditions. In springtime the 

 alga is distributed all over the Adriatic, and is most frequently found 

 on Udotea Desfontainii. 



Development of Certain Floridese.* — K. Killian describes his suc- 

 cessful experiments on the cultivation of marine algae, with a view to 

 studying their development from the earliest stages. He used cement 

 basins, into which fresh filtered sea-water was pumped day and night. 

 Cerarniacea? and other filamentous algae could only thrive if no diatoms 

 were present, and if the water had been passed through a Berkefield 

 filter. The necessary ventilation was provided by Crustacean, Echino- 

 derms and meat-eating fishes. The algal spores germinated on obliquely 

 inclined object-glasses ; and the cultures were so distributed in the 

 aquarium as to realize natural conditions as much as possible. The 

 sporelings were examined under the Microscope in flat glass vessels. It 

 was mostly possible to follow the development for at least six months. 



As regards the development of the vegetative organs, the author was 

 enabled to establish the following results. The group of Ceramio- 

 RhodomeIea3, to which the Delesseriaceaa examined by Nieuburg are 

 closely allied, showed direct development. Among Ceramiaceae, the 

 simpler forms (Callithamnium) show alternate branching, and the com- 

 plicated forms (Antithamnium) show whorled and opposite branching. 

 In Grouania the lateral branches are shortened ; in Geramium they do 

 not grow out at all. Griffithsia also shows direct development. The 

 Rhodomelea? join on to the Dasyaa. Dasya remains for a long time 

 monosiphonous. Ricardia Montagnei develops in a similar manner. 

 Not till later is a central axis developed. The Bonnemaisonniacean, 

 examined by Nageli, in which direct development is combined with the 

 formation of an attachment-disk, lead up to the second great group in 

 the developmental history of Florideae, the attachment-disk type. The 

 more simple forms of this group (Halymenia etc.), form the disk 

 irregularly, while in the higher forms it arises from regular division of 

 the spore. Further, the developmental stages of the upright shoot are 

 worthy of attention. Dudresnaya forms closely packed upright filaments, 

 in other genera the number of the entwined filaments is limited. In 

 Rhodopliyllis bifida, among others, an apical cell is formed later on, by 

 which alone the upright shoot arises. Both types of upright organs are 

 represented in one and the same family. The author considers that 

 further research is necessary before drawing up a comparative develop- 

 mental history of the Florideee, in order to decide which characters are 

 important and which unimportant, which are primary characters of 

 organization and which are secondary adaptive characters. 



Fossil Corallinacese .|— C. Samsonoff describes two new species of 

 fossil alga? preserved in the Geological Museum at Florence. The first 

 is Goniolithon Martellii, and represents a genus which has hitherto never 

 been recorded in a fossil state. It was collected in Middle Miocene 



* Zeitscbr. Bot., vi. (1914) pp. 209-78 (18 figs.). See also Bot. Centralbl. 

 exxviii. (1914)pp. 125-6. 



f Atti R. Accad. Lincei., xxiii. (1914) pp. 238-43. 



