THE ORIGIN OF INSECT TRANSFORMATIONS. 57 



EXPLANATION OF PLATE III. 



Fig. 1. — Dorsal view of female. 

 ,, 2. —Ventral view ,, 



,, 3. — Dorsal view of male. 

 ,, 4. — Ventral view ,, 



,, 5. — Palpi and mandibles. 



^be QviQin of 3necct ZTran^formatione. 



By G. H. Bryan, M.A., F.R.S. 



AT the Ipswich meeting of the British Association, Prof. C. 

 L. Miall, F.R.S. , of the Yorkshire College, Leeds, read a 

 most interesting paper on this subject, and it has occurred 

 to me that a brief account of Prof. Miall's views might be accept- 

 able to the readers of \h.Q. Journal of Microscopy. 



The subject was dealt with twenty-one years ago by Sir John 

 Lubbock in his well-known little book, published in the Nature 

 series ; but since the appearance of that work many new facts 

 have been discovered which necessitate some modifications of the 

 conclusions then arrived at by him. 



The primary object from which all animal metamorphoses owe 

 their origin is the facilitation of dispersal, and at one time it was 

 thought that some analogy existed between the transformations of 

 insects and those of many marine animals, such as the Echinoder- 

 mata and the Common Limpet. Prof. Miall considers the two 

 classes of transformations to be radically different in their nature. 



It will be noticed that both transformations result from a divi- 

 sion of labour in the two operations of feeding and dispersal, but 

 in the marine animals dispersal takes place first, and feeding 

 second ; while the insects feed in their early stages and only 

 become adapted to dispersal in their final stage. For this reason, 

 the transformations of the Echinodermata may be called Larval 

 Transformations,, since they take place before the animal has 

 grown and developed, while those of the insects may be distin- 

 guished as Adult Transformations. A closer parallel to insect 

 transformations exists in the amphibia. Thus, in the tadpole 



