74 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Reserve Substances in the Protoplasm of Infusoria.* — Dr. Fabre- 

 Domergue in discussing tbe nature of the reserve spherules found in 

 Infusoria remarks that one of tbe most prominent facts is tbe way in 

 wbicb tbey become diffluent after tbe action of ammonia, or from com- 

 pression. He seems disposed to regard tbese bodies as composed of 

 paraplasm cbarged witb a coloured liquid material wbicb is capable of 

 being absorbed by tbe paraplasm itself. This view be says is supported 

 by tbe manner in wbicb tbe spherules behave at tbe moment of their 

 disappearance by absorption. The granules do not disappear little by 

 little as they decrease in size, but tbey gradually grow pale, their out- 

 lines become less clear, while their volume remains the same, and little 

 by little tbe infusorian recovers its normal homogeneity. 



If when the infusorian has lost its spherules it be killed with 

 osmic acid, examination shows that its constitution is quite different. 

 Tbe paraplasm does not consist of isolated spherules surrounded by thin 

 layers of paraplasm, but seems as if it were contained in tbe hyaloplasmic 

 reticulum ; from which the author is inclined to believe that when the 

 paraplasm charged with colouring matter is separating from the hyalo- 

 plasm, it forms within its substance spherules, after the manner of the 

 food-boluses, which are always present in the Ciliata. 



Aegyria oliva.t — Dr. L. Plate calls attention to the unusual structure 

 of the nucleus of this Infusorian. It is composed of two halves which 

 behave differently with staining materials, in the same way as is known 

 to be the case with SpirocJiona gemmipara, Leptodisciis medusoides, and 

 some Ehizopoda. After the animal has been killed with osmic acid one 

 half of the nucleus has a darkly granular appearance, while tbe other 

 looks nearly homogeneous and clear, having a very slight granulation at 

 its foremost pole. The two divisions lie close together, but are sepa- 

 rated by a distinct line. On the application of carmine solution the clear 

 half of the nucleus becomes intensely, and the dark one very faintly 

 coloured. The nucleus of Aegyria oliva behaves, therefore, witb staining 

 materials, in a way just opposite to that of S. gemmipara, in which tbe 

 darkly granular part is the chromatic and the clear part the achromatic 

 portion. Dr. Plate considers that it would be interesting to ascertain 

 whether in the one form the nuclear division is of as complicated a 

 nature as in the other ; if it be so we should be justified in regarding 

 the separate arrangement of the chromatic and achromatic nuclear 

 elements as the cause of such a mitosis. 



New Vorticelline4 — Dr. L. Plate describes, under the name of 

 Heliochona sessilis, a new Vorticelline which he found on the branchial 

 plates of a Gammarus from the North Sea. As in Stylochona the anterior 

 end of the body is widened into the form of a funnel, and beset internally 

 with numerous cilia which whirl in the food. The head-funnel is 

 characterized by a sun-like border of thin rigid bacilli, which issue 

 from its margin. 



Two narrow and two broad sides can be distinguished in the flask- 

 shaped body ; the animal attaches itself to the branchial plate of its host 



* Ann. de Micrograplde, i. (1888) pp. 24-30. 



t Zool. Jahrb., iii. (1888) p. 173, translated in Ann. and Mag. Nat. Hist., ii. 

 (1888) p. 431. 



X Zool. Jahrb., iii. (1888) p. 172. translated in Ann. and Mag. Nat. Hist., ii. 

 1888) pp. 431-2. 



