160 



r In exchange. 



" Proceedings of the Natural His- 

 tory Society of Glasgow " 

 " Annals of Natural History " ... Purchased. 



Professor B. T. Lowne gave a resume of his paper " On the structure of 

 the head of the Blowfly larva, and its relations to that of the perfect insect," 

 which he illustrated hy diagrams drawn upon the black-hoard as he pro- 

 ceeded, apologising, however, for the absence of other diagrams which he 

 had not yet been able to complete. 



The Chairman was sure that the members would agree with him that they 

 were not only'greatly indebted to Mr. Lowne for bringing this subject before 

 them, but also for not having brought up his series of diagrams, because a 

 diagram drawn upon the board, and developed as the speaker proceeded, 

 illustrated a subject far better than could be done by pointing to a compli- 

 cated diagram. Mr. Lowne had made the view which he took of the matter 

 so plain that he was quite sure it would be clearly understood by all who 

 had listened to it, and he should be glad to hear any remarks from anyone 

 present upon this "object of the microscope,'' than which few were more 

 interesting or more common. He thought he understood Mr. Lowne to say 

 that what was commonly spoken of as the tongue — or hypo-pharynx — of 

 the cricket or the cockroach was not actually homologous, but was serially 

 homologous to the proboscis of the blowfly. 



Professor Lowne said this was so ; though functionally the same, the two 

 organs were developed from different parts. 



Mr. Tebbs said he should like to ask Mr. Lowne how it was that in the 

 gnat the labium appeared to be quite a complete and independent organ ? 

 In Bombylius they had them also quite separate, and in the sucking flies the 

 same thing also occurred. In tracing them down it was found that the 

 lancets became less developed until, in the blowfly, they were enclosed in 

 the labium. Mr. Lowne seemed to have been taking an extreme case with- 

 out bringing into relation with it the intermediate stages. In the bee there 

 was a complete set of maxillae, and so on down to the extreme case of the 

 blowfly where they had no function. 



Professor Lowne thought it would be admitted that if he was right in the 

 case of the blowfly the correctness of his view in connection with all the 

 other flies would necessarily follow. He thought that in the case of the 

 gnat and of Bombylius, the parts referred to by Mr. Tebbs were 

 the modified galea of the maxillag. In Asilus the labium was clearly dis- 

 tinct from the lips of the proboscis. In Tabanus the whole of the structures 

 were so modified that he was puzzled as to what was the actual condition ; he 

 had, however, no doubt that in the proboscis they had the galea. In the 

 bees, the tongue was a perfectly distinct structure, and there was no doubt 

 in his mind that it was a labium. With regard to the lancets they might go 

 on discussing the subject, but without conclusive results until they knew 

 what they were developed from. They had been called mandibles, but he 

 entirely dissented from that view, thinking it far more likely that they were 

 paraglossae. It was certain, however, that there was no other means of find- 

 ing out what they were except by tracing out their development. 



