246 Miscellaneous. 



cept the slight development of the larynx*, and the equality of the 

 two auricles of the heart. The digestive organs rather resemble those 

 of the Carnivora than those of the herbivorous marsupials. 



The result of these researches therefore is, that although the Da- 

 syurus ursinus resembles the plantigrade Carnivora in its appearance 

 and mode of life, its organization and internal structure place it in- 

 contestably amongst the marsupials. — Bibl. Univ. de Geneve, Dec. 

 1851, p. 346. 



On the Nervous System of Insects. By M. Dujardin. 



Persuaded that insects were not moved in their actions by instinct 

 only, but also by a peculiar intelligence, M. Dujardin has examined 

 into the organization of their nervous system, to see if it would con- 

 firm this idea which he had deduced from the observation of facts, 

 and in particular whether the supra-oesophageal ganglion, to which 

 the name of ' brain ' had been given, although only on account of ana- 

 logy of position, did not present another resemblance of much greater 

 importance, that of intimate structure and organization, — in other 

 words, whether insects had, or had not, a brain. The results of his 

 observations are, — 



1. That in some articulated animals there exists a true brain, of 

 which the structure and volume correspond with the development of 

 the intellectual faculties : thus, if we compare the volume of the brain 

 of the ant with that of the cockchafer, we shall find that they are as 

 1-7, whilst the volumes of their bodies are as 1— 100. 



2. That the brain, or supra-cesophageal ganglion, contains sym- 

 metrical bodies of a well-determined form, to which he has given the 

 name of corpora pedunculata (corps pedoncules) ; these organs are 

 more or less completely surrounded by a pulpy cortical substance, 

 which is relatively less considerable in the most intelligent insects, 

 and predominates in those in which intelligence is masked by instinct, 

 whilst it occurs alone in those insects which are only endowed with 

 the latter faculty. 



3. The same pulpy substance appears also to occur by itself in 

 those ganglia of the thorax and abdomen which assist in purely in- 

 stinctive actions. — lb. Sept. 1851, p. 74. 



OBITUARY. WILLIAM THOMPSON, F.L.S., 



PRESIDENT OF THE NATURAL HISTORY SOCIETY OF BELFAST. 



It is with much regret we have to record the death of Mr. William 

 Thompson, of Belfast, which took place very suddenly in London 

 on Tuesday morning Feb. the 1 7th. Mr. Thompson had been visiting 

 our metropolis chiefly with a view to making arrangements for the 

 approaching meeting of the British Association in Belfast, of which 

 he had been appointed by the Council a Vice-President. Mr. Thomp- 

 son was well known as a writer on various branches of natural history. 

 Science is indebted to him for the ardour with which he investigated 



* The slight development of the larynx is a character peculiar to the 

 marsupials, which accounts for these animals being generally mute. Like 

 them, the Dasyurus at Amsterdam never emitted any sound except a low 

 grunting, and even this very rarely. 



