PHILOSOPHICAL TRANSACTIONS. 



X. The Bakerian Lecture. — On the Organs of Reproduction, and the Development 

 of the Myriapoda. — First Series. By George Newport, Esq., Member of the 

 Royal College of Surgeons, and of the Entomological Society of London. Com- 

 municated by Peter Mark Roget, M.D., Sec. R.S. S^c. S^c. 



Received June 17, — Read June 17, 1841. 



The development of the Myriapoda has hitherto been only partially investigated. 

 It is, nevertheless, a subject of great importance to the comparative anatomist, from 

 the remarkable fact that it takes place in a manner entirely different from that of 

 most of the higher Articulata, to some of which the Myriapoda are closely allied both 

 in habits and structure. The true Insecta arrive at their perfect state by an aggre- 

 gation or apparent diminution in the number of their segments, but the Myriapoda, 

 on the contrary, by a repeated increase of these parts, which in many instances are 

 multiplied to several times their original number. This addition of segments, 

 during the growth of the animal, occurs throughout the whole class, and is one of its 

 chief characteristics. This fact was first noticed long ago by Degeer, but since the 

 period of his observations nothing further was added to our knowledge until it was 

 fully confirmed by the careful investigations of Savi, and also by the more recent 

 labours of Brandt, Gervais, and Waga. But excellent as are the observations of 

 these naturalists, some of the most important circumstances connected with them 

 have been entirely overlooked, both as regards the condition of the embryo on leaving 

 the ovum, and also as regards the manner in which the new segments are developed. 

 M. Gervais* has pointed Out a circumstance in which the Scolopendradae diflfer from 

 the lulidae in the development of the legs, but no precise account, so far as I have 

 been able to ascertain, has been given of the production of the segments. In the ob- 

 servations which I now have the honour of submitting to the Royal Society, I propose, 

 first, to examine the organs of reproduction, and then to show the various changes as 

 they occur in the development of lulus terrestris, one of the commonest species of 

 the lulidge of this countiy. 



* Annales des Sciences Natur., torn. vii. Janvier 1837, p. 35, &c. 

 MDCCCXLI. P 



