Insects. 6911 



success, till the following summer, when the insect upon which they 

 are parasitic has not only selected a place in which to build, but has 

 made some progress in the work of building, it being most uncertain 

 in what precise locality the wasp may construct its nest. It may be 

 somewhere not very remote from the spot chosen by its predecessor; 

 but it will be by the merest accident if the nest is found to be placed 

 so near the cavity in which that of the previous year was situated as 

 to be accessible to larvpe produced from eggs deposited in that cavity. 

 Whatever, therefore, the males of this parasite may do, the females 

 must of necessity hybernate. 



I have already stated that my observations upon these parasites, at 

 the time they were emerging, extended over a period of five days. 

 During the latter part of that time the combs in which they had been 

 bred were kept suspended under an aquariura-glass, food being placed 

 near the combs that the attendant wasps, which were congregated 

 between them, might be enabled to feed the larva3 the cells still con- 

 tained, — a task they continued unremittingly to perform, without 

 evincing any great desire to escape from their confinement. 



On concluding my observations upon the parasites the combs were 

 returned to their place near the nest from which they had been 

 removed, when numbers of workers belonging thereto were again 

 observed to be employed in the fabrication of a fresh covering, to 

 which daily additions were made for several weeks, the utmost activity 

 prevailing during the time, and the nest becoming more and more 

 populous. Toward the end of September, however, the work became 

 slack, the workers having fallen off very considerably in number. On 

 again removing the covering, which was done early in October, a few 

 eggs and a few spun-up larvae or nymphse were the only objects the 

 combs contained. Most of the cells had been cleared out, and their 

 walls well nigh demolished, while no additional ones had been formed 

 since the first removal of the nest, on the 25th of July. 



It may be worthy of remark that, from first to last, not a single male 

 appeared to have been produced in this nest; at any rate I never 

 observed one. 



S. Stone. 



On the Transverse Fission of Aiptasia Couchii* — As I do not find anything in the 

 history of Aiptasia Couchii in your ' Actinologia Britannica' concerning its system of 

 increase, the facts I can communicate may be of interest. About the end of last 



* Extracted from a letter to P. H. Gosse, Esq., F.R.S. 



