INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 937 



median plane, where the cells of the neurilemma are best developed ; 

 they vary greatly in size. 



Referring to the paper for the other important details with which 

 it abounds, we find, as a general conclusion, that the separate ganglia 

 of the adult do not arise from any new formations, but from the 

 extension of the ventral cord of the larva ; the peripheral nerves are 

 the same in both ; there is no histolysis of the larval nerves, but a 

 growth of the nerve-trunks. In both, there are the same number 

 of ventral ganglia, both have similar relations to the tracheal system, 

 and intermediate conditions are to be seen in the pupa. There is no 

 " dotted substance " as Leydig understands the term, and no true 

 transverse commissures ; instead of these there are a large number of 

 transverse bundles, which, on the one side, arise from the ganglia, 

 and on the other, form the peripheral nerves. 



Activity of Bees.* — The paper of E. Erlenmeyer and A. v, Planta- 

 Reichenau is a sequel to former reports f on a similar subject, being 

 further experiments made to ascertain whether the wax secreted by 

 bees is derived from the sugar and other carbo-hydrates which are 

 found in the nectar of the flowers, or from such nitrogenous matters 

 as exist in the pollen. 



A healthy swarm was bought in February, well cared for and 

 fed, and at the beginning of the experiments was in a very healthy 

 condition. A determined number of the bees was carefully weighed, 

 and, with the queen, transferred to the experimental hive, which was 

 furnished with all appliances requisite for carrying out the experi- 

 ments. The food was weighed in tared capsules. Before tlie 

 weighing of the swarm, fifty of the bees were killed with chloro- 

 form vapour, and used for fat and nitrogen determinations. Each 

 experiment lasted four days and four nights, and for a whole day 

 the animals were confined to tlie hive. 



The bees were first fed with a solution of sugar-candy, and a 

 remarkable yield of wax was the result. The suggestion was made 

 that the albumen in their bodies contributed to it, but both the 

 nitrogen and the fat were the same before and after the experiment. 

 A second trial w.is made by feeding the bees on honey, but the 

 quantity of wax produced was less. Further observations, extended 

 over longer periods, were made, with a view to see what etfect tempe- 

 rature would have on the production of wax. The first, made during 

 favourable weather, on sugar-candy solution mixed witli 1 per cent, of 

 wheat-flour, gave very good results ; the second, carried on simul- 

 taneously, on honey and wheat-flour, gave good, but still inferior 

 results ; the third, with the same food as the first, but in less favour- 

 able weather, gave a much inferior yield ; in another experiment the 

 small proi)()rtion of • 22 per cent, dry gelatine was ailded to tlie sugar 

 solution, witli un.satisfactury results, whilst a much larger proportion 

 of gelatine, 1^ per cent., added to honey produced a very largo 

 amount. When, however, the quantity of gelatine was increased to 



* 'Bicd. Ci'ntr.,' 1880, pp. 191-3. See Mourn. Ch.m. Soc.,' Ahetr. xxxviii. 

 (1880) j.p. 72.'') C. 

 t IM.l.. p. 115. 



