1 86 1 .] Professor Westwood on the Metamorphoses oflmects, 375 



WEEKLY EVENING MEETING, 

 Friday, May 24, 1861. 



The Duke of Northumberland, K.G. F.R.S., President, 

 in the Chair. 



John O. Westwood, Esq. M.A. F.L.S. 



HOPB PBOFESSOB OF ZOOLOGY IK THE UNIVERSITY OF OXFOSD. 



On the Metamorphoses of Insects, 



The marvellous in all ages has taken precedence in the human mind 

 over the everyday phenomena of the routine of existence, and every 

 thing not exactly in accordance with our ordinary ideas has become 

 invested with something of the marvellous. Hence the metamor- 

 phoses sung by Ovid have been admired and extolled from the Roman 

 age to our own, and old and young alike enjoy our Christmas panto- 

 mimes as much on account of the transformations effected by the wand 

 of Harlequin, as for the gorgeous scenery with which they are ac- 

 companied. In nature, however, " truth is stranger than fiction," as 

 manifested in the extraordinary changes of the animals which formed 

 the subject of the discourse. To suppose a creature existing at one 

 period of its life as an egg ; then as a serpent ; next, as burying itself 

 in the ground, and encasing itself in a solid tomb, in which it remains 

 for a time swathed up like an Egyptian mummy, and from which it 

 ultimately bursts forth a changed and glorious being, flitting on 

 delicately-constructed wings from flower to flower, would be regarded 

 as the height of imagination without the truth were before us. And 

 yet these are the transformations which, year by year and day by day, 

 are being effected before our eyes in our fields and gardens. 



There are two leading operations to which every living thing is 

 constantly subjected — the taking in of new, and the rejection of 

 already worked-up materials. Breathing and exhaling are instances 

 of these operations, and it is mainly owing to these operations that 

 growth and the accompanying rejection of portions of the animal frame 

 (constituting what has been termed metamorphoses, in their most 

 striking forms) are effected. In the vertebrated animals the fleshy 

 covering is increased by constant depositions, but in animals encased 

 in an external skeleton there is a restriction and obstruction offered by 

 it to their growth, and the hard outer case must consequently be 

 periodically got rid of. And it is this periodical "casting off" the 

 outer envelope which results in the transformations of insects. A 



