154 SUMMARY OF CURRENT KKSKAIiCHKS RELATING TO 



P. oblonga Williamson. In Nouria harrisii the test is entirely composed 

 of sponge spicules arranged in a single layer with their axes arranged 

 more or less parallel to the long axis of the test. The " skill " — or 

 "purpose" —exhibited by this little organism in the building of its 

 test reaches its most remarkable development in the construction of the 

 aperture. The spicules designed to form the terminal portion of the 

 shell are selected by the organism of such size and shape as to form a 

 perfectly tapered neck with a circular aperture, round which the points 

 of the spicules often form a regular fringe. There are sometimes pro- 

 jecting spicules pointing aborally, which may keep the shell erect in the 

 surface layer of mud. with the aperture upwards. Iu the third species, 

 N. compressa, the shell is also composed of sponge-spicules, but there 

 are occasional sand-grains or mineral flakes. 



The Kerimba material was collected by Dr. J. J. Simpson. It has 

 yielded 460 different species and varieties, including many new forms 

 besides India and Nouria. 



Conjugation in Amoeba.* — R. E. Hedges describes and figures the 

 process of conjugation in a small species of Amozba, which he took to be 

 A. Umax. The amoebae could be seen very clearly on the slide, but they 

 were so filled with bacteria that it was in most cases impossible to dis- 

 tinguish a nucleus. Two amoebae came into contact on the slide, and 

 after remaining cpuet for about 20 seconds the distinct line of contact 

 between the two individuals broke through for a portion of its length, 

 and the protoplasm of one flowed into the protoplasm of the other. 

 The opening grew larger as the protoplasm flowed through, and the 

 flowing did not take more than three or four seconds to be completed. 

 The union was complete and not partial or temporary, therefore the 

 word copulation is used instead of conjugation. The two individuals 

 were of nearly the same size, and the result of copulation was a slightly 

 larger Anwba. The transference of protoplasm was seen to be complete, 

 none being cast off in the process. Several pairs were observed, and in 

 one case the resulting Amceba was kept under observation for 4 hours. 

 After remaining still for a few minutes, it crawled slowly into a mass 

 of bacteria and remained there, apparently feeding, for the rest of the 

 time. During that period it was approached by another individual five 

 separate times, but after touching the two separated at once. The 

 changes of shape and the development of a " brown body " are described 

 and figured. 



African Species of Volvox.f — C. F. Rousselet has a note on the 

 sexual stages of Volvox africanus and V. rousseleii, from German East 

 Africa. These sexual stages were collected by A. W. Jakubski, of 

 Lemberg ; the vegetative colonies, previously described by G-. S. West, 

 were collected by Leiper near the northern shores of the Albert Nyanza 

 and by Rousselet at Gwaai Station in Rhodesia. 



* Zool. Anzeig., xliv. (1914) pp. 214-19 (5 figs.), 

 t Journ. Quekett Micr. Club, xii. (1914) pp. 393-4. 



