British Association. 1835 



its eggs in the wood, and then when the larvae are hatched they eat their way out. — 

 Mr. Spence stated that other insects had the same habits. An insect, a species of 

 Anobium, did great damage in the neighbourhood of Brussels. — Prof. Esmark stated 

 that the Callidium Bajulus was a rare insect in the eastern parts of Norway, hut in 

 the southern parts it was very common, and destructive to the timber of forests. 



1 On the Structure of the Larva of certain Acari,' by Prof. Allman. — The author 

 demonstrated in the six-legged larva of Halarachne Halichceri (Allm.), a digestive ca- 

 nal which expands on either side into two great ccecal pouches. Two long coeca also 

 may be seen opening into the rectum near its termination, and from this point may be 

 traced forwards on each side till they enter the basal joints of the anterior pair of legs. 

 A large nervous mass placed beneath the oesophagus was also pointed out, and the 

 fourth or posterior pair of legs, which are afterwards to become developed, may be seen 

 in a rudimental condition, confined as yet beneath the integument. No trace of 

 tracheae could be detected, though these are very evident in the adult, and the author 

 was of opinion that the respiratory function does not become specialized till after the 

 development of the fourth pair of legs. 



Dr. Allman also read a paper ' On the Locomotive Larva of Plumatella fruc- 

 ticosa.' 



A paper was also read by Dr. Allman ' On the Development of Notodelphys, 

 (Allm). y a new genus of Entomostraca.' 



Mr. L. Reeve stated that the common cowrie passed through the metamorphosis 

 that Prof. Allman had mentioned in other Mollusca. — Mr. Westwood drew attention 

 to the development of the Crustacea, in which when young the representatives of the 

 legs in the adult animal were shown by a series of eight moveable appendages round 

 their jaws. — Dr. Melville referred to the experiments of Sir John Dalyell and Mr. 

 Goodsir, on the reproduction of the lost parts in various Crustacea. 



Wr. Westwood made some remarks on the existence of the potato-disease in Ox- 

 fordshire. Some potatoes of his own had been attacked this year, and in three diffe- 

 rent districts around Oxford he had observed its presence. As an entomologist, he 

 wished to deny most distinctly that he thought the disease arose from the attacks of an 

 insect. It had been stated by Mr. Smee that it arose from the attacks of a new Aphis 

 which he called vastator, but this Aphis, far from being new, had been described many 

 years ago and was a very common insect on decaying plants. Another gentleman pro- 

 posed to call the insect A. pestilens. Mr. Westwood drew attention to the ignorance 

 such observers displayed, as rendering it necessary that zoology should be taught as a 

 branch of science. He was sorry to be speaking on this subject in an English Univer- 

 sity where neither zoology nor comparative anatomy were recognized as branches of 

 education. 



Mr. J. E. Gray stated that he had compared some specimens of the Aphis vastator 

 with species of Aphides in the British Museum, and found that under this name Mr. 

 Smee had included three or four well-known species. — Dr. Lankester drew attention 

 to a bundle of potato-stalks which he had brought from Pangbourne, which gave every 

 sign of disease, but not an Aphis could be found upon them. One fact of this kind 

 was sufficient to prove that the disease had no dependence upon the insect. He had 

 heard from a gentleman in Manchester that potatoes sown in new soil on Chat Moss 

 were free from the disease, whilst those sown in old soil all had the disease. This 

 looked as if the inorganic constituents of the soil or potato were the source of the dis- 

 ease.— Mr. Babington referred to the potato-stems from Pangbourne. He had ex- 



