16 



SCIENTIFIC RECREATIONS. 



tinguishable, branching out from an organism remarkable for its simplicity. 

 We often amused ourselves by examining, almost at hazard, everything that 

 came within our reach, and sometimes we were led to make very instructive 

 investigations. When the sky was clear, and the weather favourable to- 

 walking, we encouraged our young people to run about in the fields and 

 chase butterflies. The capture of butterflies is accomplished, as every one 

 knows, by means of a gauze net, with which we provided the children, and 



Fig. 10. Arrangement of a microscopic aquarium for examining infusoria* 



the operation of chasing afforded them some very salutary exercise. It 

 sometimes happens that butterflies abound in such numbers, that it is com- 

 paratively easy to capture them. During the month of June 1879, a large 

 part of Wetern Europe was thronged with swarms of Vanessa algina 

 butterflies, in such numbers that their appearance was regarded as an 



important event, and attracted the ively attention of all entomologists 

 (fig. 1 1). This passage of butterflies provided the occasion for many interest- 

 ing studies on the part of naturalists. 



We cannot point out too strongly to our readers that the essential condi- 



