NOTICES AND REVIEWS. 47 



01* even months. Onr author, too, wliile giving insects the reputation 

 of having a wonderfully keen development of the sense of smell and 

 discrimination of scents, illustrated in the familiar })henomenon of 

 " assembling," says, with regard to the selection of tlie food-plant by 

 the perfect insect on which to lay lier eggs : — " Our only solution of 

 the problem is, to attribute the whole thing to that inexplicable 

 quality which we are pleased to term natural instinct." The "we" 

 here would pi'obably include some of the old Latin and Greek philoso- 

 phers, and even some of the British sages of the middle ages. But such an 

 explanation as this is out of place in a book published at the end of the 

 nineteentli century, circulars concerning the sale of which have been 

 sent to the Fellows of the learned Societies. The chapters on the " Egg " 

 and "Larva" are full of the well-worn platitudes which every fairly 

 educated man, without any special knowledge of the subject, 2:)icks up ; 

 but the way in which a Nymphalid pupa is able to wriggle out of the 

 larval skin and suspend itself by its anal segment is characteristic of the 

 book. Our author writes : — " The thing is managed in this way. As the 

 skin slowly splits through the wrigglings of the apparently uncom- 

 fortable occupant, it is gradually pushed backward — that is, upward — 

 till it is in a shrivelled condition and the body of the insect is nearly 

 free. But the chrysalis thus brought to light is provided with little 

 hooks on the end of its 'tail,' by which it can attach itself to the 

 irregularities of the crumpled coat. Its conical abdomen is also very 

 flexible, and it can, by bending this, seize hold of a ridge in the skin, 

 holding it between the segments. Thus, although practically quite 



free from its old garb, it never falls to the gTound The 



newly-formed chrysalis desires to be entirely independent of its cast- 

 off skin, and to suspend itself directly from the silky carpet it has 

 prepared. To this end it works steadily for a time, alternately bending 

 its supple abdomen from side to side, gripping the folds of the skin 

 between the segments, pulling its body a little higher at each move- 

 ment, and securing itself at each step by the little hooks at its 

 extremity. So it climbs, and at last it reaches the network of silk 

 fibres, and thrusts the tip of its abdomen among them till some of the 

 hooks have taken hold." Quite interesting this if it were true. 

 We are quite aware that this was the explanation given by Kirby and 

 Spence three-quarters of a century ago. We are quite aware that it 

 has been copied, paraphrased, and translated, with or without quotation 

 marks, by writers of books for three-quarters of a century. But it is 

 not true, as our author will discover if he examines the phenomenon 

 next summer for himself, or looks up the remarks of Dr. Osborne and 

 others in the back numbers of the Ent. Mo. Mag. On p. 47, the 

 author states that experiments have been performed in which pupae 

 have been placed " in an ice-house, and the emergence of the j^er- 

 fect insect has been delayed for many months and even years, and 



then the winged insect has made its appearance as if nothing 



unusual had happened." We would like to have the references to these 

 experiments. Prof. Weismann's and Mr. Merrifield's are the most 

 successful experiments of the kind that have been carried out, and 

 their experiments certainly prove that such insects as do emerge show 

 remarkable signs of something very unusual having happened, as may 

 be seen from the Plates in the Trans. Eat. Sac. of Land, accompanying 

 Mr. Merrifield's papers. We take leave to doubt the fact that any 



