860 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the species and varieties, and a list of seventy-eight works dealing 

 with Fresh-water Sponges. The illustrations relate chiefly to the 

 spicules and the structure of the gemmule. Unlike Dybowski, the 

 author does not employ positive measurements of the parts in his 

 descriptions. 



Bavarian Fresh-water Sponge.*— Mr. H. J. Carter records the 

 discovery of spicules of Sponcjilla in the dark-brown argillaceous 

 diluvium of the Altmiihl valley, Bavaria. 



African Fresh-water Sponges.t — M. Hilgendorf describes two 

 Spongtllce {S. miens Carter and S. Bdhmii n. sp.) collected by Dr. E. 

 Bohm in the Eiver Ugalla, near Lake Tanganyika. Until now the 

 occurrence of a fresh-water sponge from Africa had never been 

 proved. 



Protozoa. 



Chlorophyll in Vorticellae.J — T. W. Engelmann describes the 

 occurrence of undoubted chloroj)hyll in certain Vorticellinfe. Growing 

 on filaments of VaucJieria, both living and dead, he found, along with 

 Vorticella camjKinula and nehulifera, others of a diffused green colour, 

 distinf^uished also by the narrower and more delicate circular marking 

 of the body, and the greater transparency of their endoplasm. The 

 colouring matter did not belong at all to the endoplasm, but entirely 

 to the ectoplasm, and to the cuticle and the very narrow protoplasmic 

 subcuticular layer. In fresh animals the colour was perfectly homo- 

 geneous, as in the chromatophores of plants, but somewhat paler. 



In order to determine whether the colouring substance was true 

 chlorophyll, i.e. a chromophyll with true power of assimilation, 

 Engelmann employed the bacteria-method proposed by himself.§ 

 Careful experiments proved beyond a doubt that these Vorticellce had 

 the power of decomposing carbon dioxide, and giving out free oxygen 

 into the air in the presence of light. This the author regards as the 

 first instance known of a true chlorophyll connected with the living 

 protoplasm of an animal, and not with vegetable organisms con- 

 tained within it. The quantity of oxygen given off" is, however, small, 

 partly in consequence of the small amount of chlorophyll contained 

 in the ectoplasm, partly because a considerable portion of the oxygen 

 is immediately again required by the animal itself fur its respiration. 



Spectroscoj)ic examination again showed the spectrum of the green 

 pigment of the VorlicellcB to be identical with that of vegetable 

 chlorophyll. The reaction towards concentrated sulphuric acid and 

 other chemical tests, led to the same conclusion. 



. Although this Vorticella is the only animal in which Engelmann 

 has at present proved the existence of chlorophyll, he has long been 

 acquainted vdih. specimens of Cotliurnia crystalUna of a diffused green 

 colour ; and he suggests whether many of the bluish, brownish, violet, 

 and other pigments which are diffused through the ectoplasm of some 



* Ann. and Mag. Nat. Hist., xii. (1883) pp. 329-32 (I pi.), 

 t SB. Gesell. Naturf. Fieunde, 1883, May 22iid. 

 % Onderz. Pbys. Lab. Utrecht, iii. (1883) pp. 147-69 (German). 

 § Sec this Journal, i. (1881) p. 962. 



