230 SUMMARY OF CURRENT RESEARCHES RELATING TO 



with a homogeneous mass of protoplasm, with scattered ntfclei. At 

 the blind end of the tubule these nuclei multiply by fission. In 

 Forficula, where the ovum possesses only a single nutritive cell, the 

 process is most easily seen. At a short distance from the blind end 

 a mass of protoplasm arranges itself round each nucleus ; from each 

 of these ovarian cells thus formed, the " follicle-cells " are derived by 

 groups of granular refringent particles passing out of the protoplasm, 

 and arranging themselves around the cell ; these follicle-cells then 

 increase by division. Tlie " nutritive cell " is formed by a similar 

 process ; a mass of granular protoplasm, from the neighbourhood of 

 the germinal vesicle, passes towards one end of the oval egg-cell : it 

 gets nipped off here, and forms a nutritive cell, which is, together 

 with the ovum, surrounded by the follicle-cells. Thus both the 

 follicle and nutritive cells are portions eliminated from the egg-cell. 



In a second paper * M. Sabatier describes the second variety of 

 ovary — that in which the vitellus remains at the blind end of the 

 tubule, as in Coleoptera and Rbynchota. The terminal filament con- 

 sists of a mass of pyramidal cells surrounding a lumen, and enclosed 

 by a membrane. Beyond this is the ovarian swelling, which consists 

 of four layers : (1) a thick layer of large nutritive cells ; (2) within 

 this a mass of delicate fibres arranged longitudinally, suspending the 

 ovules, and connecting them with the nutritive cells ; (3) the ovules 

 in the lower central region ; (4) a network of small (follicle) cells, 

 which separate the ovules from one another. The development of this 

 ovary was traced in Nepa cinerea. 



At first the ovarian swelling has the same structure as the terminal 

 swelling ; at the base of each primitive ovule, nutritive cells are formed 

 by endogenous division, and at the same time follicle-cells are also 

 formed. As the ovum enlarges, it pushes its way into the central 

 lumen, and carries with it a small prolongation or cord of nutritive 

 cells ; thus, as in the first variety of ovary, both nutritive and follicle 

 cells are eliminated elements. The difference between these two 

 varieties appears to be that in Lepidoptera, &c., the Ovary remains 

 solid, and the ova surrounded by their nutritive cells; whereas in 

 Coleoptera, &c., a central cavity is present, in which the ovules are 

 suspended, and are thus able, by elongation of the suspending cords, 

 to be removed from their nutritive cells. 



Gustatory Organs of Insects.f — ^Herr F. Will, after a short his- 

 torical introduction with regard to the gustatory organs of insects, 

 as to which our knowledge is still in a very elementary condition, 

 gives an account of his own experiments. He commenced with bees, 

 wasps, and ants, which he first kept for some time without food so as 

 to make them hungry ; he soon found that hungry Hymenoptera 

 make very little choice, and he was therefore obliged to alter his 

 plan of experimentation ; he made use of pulverized sugar, alum, and 

 crystalline dolomite ; the alum was found to be nasty by bees, who 

 took it at first when it was put in the place of the sugar, but tried to 



* Comptes Renilus, cii. (1886) pp. 267-9. 



t Zeitbchr. f. Wiss. Zool., xlii. (1885) pp. G71-707 (1 pi.). 



