130 



When on the point of becoming a pupa, the nervous lobes above 

 the oesophagus are found to be considerably enlarged, and to have 

 assumed more of the appearance of a cerebral mass ; while, at the 

 same time, the nervous cords descending from them are shortened 

 and thickened. The ganglia are brought nearer together, and their 

 intervening cords lie between them in an irregular manner, the 

 ganglia themselves being retained in their proper places in the 

 segments by the nerves running transversely from them. The 

 nerves of the antennae are enlarged, and the optic nerves are become 

 much thicker and shorter than before. There is a remarkable en- 

 largement of the thoracic nerves, particularly of those sent to the 

 wings ; and those belonging to the posterior pair of legs are cu- 

 riously convoluted within the thorax, preparatory to their being un- 

 coiled at the instant of the change being made to the pupa state. 



These changes are followed minutely through several stages of 

 development. The author expects to be able to lay before the So- 

 ciety, in a subsequent paper, the results of his investigation of the 

 remaining stages, and to offer some observations upon the manner 

 in which these changes are effected. 



The Society then adjourned over Whitsun Week to the 21st of June. 



June 21, 1832. 



HIS ROYAL HIGHNESS THE DUKE OF SUSSEX, KG., 

 President, in the Chair. 



Papers were read, bearing the following titles : 



1. "An Account of the magnetical Experiments made on the 

 Western Coast of Africa in 1830 and 1831," by Commander Edward 

 Belcher of H.M.S. Etna. Communicated by the Rev. George Fisher, 

 M.A. F.R.S., through Captain Beaufort, R.N. F.R.S. 



The object of the inquiry specified in this paper, and of which the 

 results are given in a tabular form, was to determine the relative 

 horizontal intensities of terrestrial magnetism on the different parts 

 of the coast of Africa which the author has been lately employed in 

 surveying. The experiments were made with four needles con- 

 structed by Dollond on the model of those of Professor Hansteen ; 

 and the permanence of their magnetism during the voyage was veri- 

 fied by a comparison of trials made in England before and since the 

 voyage. Errors arising from local causes of irregularity were 

 guarded against by varying the places of observation at each station, 

 and taking mean results. 



2. "On the Use of a substance called the False Tongue in Foals," 

 by Professor Sewell, of the Royal Veterinary College. Communi- 

 cated by Sir Charles Bell, F.R.S. 



The substance called the false tongue, which is thrown out from 

 the mouth of the foal, either at the period of birth, or shortly before 

 it, and to which various whimsical uses and virtues have been 

 assigned, is conceived by the author to be requisite in this animal 

 or the action of sucking, in consequence of its not respiring through 



