26S 



HARDWICKE'S S CI E N C E- GOSSIP. 



matter of temperature, aeration of water, the pre- 

 sence of vegetable growths, and so forth, is suited 

 to the health of the remainder. But insects, non- 

 aquatic, require a very great variety of conditions 

 to insure their well-being and growth to maturity. 

 It is not impossible to carry out these conditions 

 with the exercise of caution 'and patience, but 

 separation is almost unavoidable, unless you are 

 taking species in those stages when they are quies- 

 cent, or nearly so, as in the egg and pupa states, 

 which are not likely to be particularly attractive in 

 the vivarium — at least in most species. The larvae 

 of insects require treatment of the most diverse 

 kind; and this is 'true even of some species which 

 have very close affinities. 



So, too, is it more or less the case with insects in 

 the imago state : if we wish to see them to advan- 

 tage as prisoners, we must give them an abode 

 which will afford them all facilities for pursuing the 

 course of their existence as they would if at large. 

 With many insects it is impossible to manage this,, 

 unless we give to a species a separate abode ; and 

 with probably the majority, in most cases, no con- 

 trivances can make them fully at ease when they 

 are removed from their natural habitats. Eor it 

 happens very unfortunately that the species which 

 we think most fitted to adorn an insect vivarium 

 will not take at all kindly to it ; a notable example 

 being furnished by the Diurnal Lepidoptera ; and 

 only a few of the night-flyers in that order can be 

 introduced in the imago state into the vivarium. 



In the frontispiece to a work upon the subject, the 

 artist depicts a scene, over which I have enjoyed 

 many a laugh with friends. The elegant structure 

 contains both land and water, the latter, however, 

 appearing to preponderate almost as much as it 

 does upon the surface of the globe — an arrangement 

 certainly not desirable in actual practice ; but the 

 artist may be conceded some liberties. 



Passing over the dwellers beneath the mimic 

 flood, when we proceed to examine into the habi- 

 tants above, we find a very amusing commingling of 

 species. There are several larvae, one or two of 

 which are recognizable as the spiny larvae of one 

 of the Vanessas ; there is also a hairy individual 

 supposed to be a Tiger, and a caterpillar of some 

 Hawk-moth, presumably that of the Privet Hawk 

 {Sphinx ligustri). 



Careering about in the vacant space above, 

 we have the moth of the last-named species, and if 

 we are startled to find it in all its winged glory, 

 while the caterpillar producing the same species is 

 also feeding within, we must set the circumstance 

 down to the remarkable influence of the vivarium, 

 which may be supposed to have prolonged the life 

 of the moth beyond its wonted limit. Various 

 butterflies arc recreating themselves, the Large 

 White, the Clouded Yellow, and the Purple Em- 

 peror being prominent, the last of these being re- 



presented in such a position, just above the water, 

 that one would suppose, like Venus, he had just 

 emerged from it. 



Now with regard to the demeanour of the Privet 

 Hawk-moth in such circumstances I can speak 

 positively, having kept a number in a good-sized 

 vivarium, made by way of experiment at a time 

 when I was desirous of obtaining eggs of the species. 

 Throughout the day they are placid enough, but 

 towards evening there was a mighty commotion ; 

 they dashed to and fro on their strong pinions, 

 heedless of opposing glass and zinc ; the result being 

 seen in the morning in fractured antenna? and wings 

 soiled and frayed. 



Allowing for difference of habit, a nearly corre- 

 sponding result ensues with the butterflies. A few 

 species indeed are sluggish, and take but short 

 flights, such as the Greasy Eritillary ; the majority 

 speed rapidly on the wing, while some rise upwards 

 with considerable force. All these will, as a rule, 

 remain inactive enough while the vivarium is in the 

 shade ; but when the sun is allowed to shine upon 

 it, then begin their rapid gyrations. Like our well- 

 known house-fly, they sweep towards the glass, 

 mistaking it for empty space through which they 

 can pass. We have all seen flies strike themselves 

 repeatedly against window-panes, and retire seem- 

 ingly none the worse ; it is not so with butterflies, 

 whose plumed wings are by no means improved by 

 such muscular feats. 



I have enclosed flowers with these insects in a 

 vivarium, but they have hardly ever deigned to alight 

 upon, or take any notice of them. In the same 

 engraving to which reference has just been made, 

 there are also introduced some specimens of the 

 Neuropterous order, including dragon-flies of the 

 larger species. It is a matter of familiar observa- 

 tion to every one, that these insects take long 

 flights, hawking to and fro after their prey. They 

 therefore brook confinement exceedingly ill, and, in 

 fact, if the owner of the Insect Vivarium has well 

 supplied his menagerie with curious examples, he 

 will have reason to rejoice if his dragon-flies are 

 inactive, for when hunting they can destroy a good 

 number of insects in a very short space of time. A 

 vivarium would need to be large indeed to allow 

 sufficient scope for the evolutions of the majority of 

 winged insects. 



Then again, as to the uses of vivaria in the matter 

 of larva - rearing, the keeping of a number of 

 different species in a general cage almost precludes 

 that proper attention to the wants and habits of 

 each, which is so necessary for their successful 

 culture. And a most serious disadvantage is this, 

 that insects of all the orders display an inclination, 

 constantly or occasionally, to make other insects 

 their prey ; nor will the best supply of food, and 

 frequent watching, obviate this. Especially will 

 this happen if we have introduced a pond in our 



