176 



HARDWICKE'S SCIENCE-GOSSIP. 



their clearance. Mr. Lloyd told me that the nui- 

 sance was still greater at the Hamburg aquarium, 

 where they appeared in like manner with the first 

 supplies of animals. 



Now that the authorship of the "Vestiges" is 

 fully revealed, there is no tr-eason in gossiping about 

 the condition of the secret. Long ago when the book 

 was new, and many of the large family of the author 

 were little children, I spent many bright evenings in 

 Doune Terrace, in the midst of the circle of his inti- 

 mate friends, which included all the eminent men and 

 women of Edinburgh ; for Robert Chambers, although 

 distinctly on the liberal and progressive side in 

 everything, was so free from mere partisanship that 

 representatives of every social set in Edinburgh, 

 excepting the extreme Calvinists, were present at his 

 larger gatherings. 



Somehow, but nobody could say definitely, how 

 or why, we generally believed that Robert Chambers 

 was the author of the book ; nobody asserted it, 

 simply because nobody positively knew ; all respected 

 the secret and understood well enough why it should 

 be kept, and therefore scrupulously avoided any 

 discussion of the subject in the presence of the 

 supposed author. To have asked him anything about 

 it would have been regarded by all as a gross imper- 

 tinence. The chief confirmation of my own sus- 

 picion was supplied by the fact that I never heard 

 him allude to the book, then so fruitful a subject of 

 conversation, and rarely to any of the topics discussed 

 in it, though I knew that he was a self-taught 

 geologist and naturalist, with that freedom from text- 

 book trammels and scholastic orthodoxy that leads to 

 the philosophical breadth and bold originality of 

 thought that characterise the work, as well as to the 

 gaps in the knowledge of detail that it also betrays. 

 As I heard George Combe remark, he never denied 

 the authorship. 



W. Mattieu Williams. 



THE TEETH OF THE HOUSE-FLY. 



By W. H. Harris. 



TN the year 1S78 there appeared in Science- 

 -L Gossip, at page 147, a very interesting paper on 

 "The Teeth of the Blow-fly," accompanied by an 

 accurate illustration enabling anyone to recognise 

 these organs in a properly prepared object. 



Having prepared some lips of the blow -fly by the 

 method therein indicated, in order to make myself 

 thoroughly assured of the presence of these organisms, 

 I was induced to seek further among the diptera, with 

 the view of ascertaining if other members of this large 

 order presented a similar development. In very many 

 cases I have found this to be so. The teeth in different 

 species vary not only in number but also in form, so 

 far as their free ends are concerned, but in one 



particular they all appear to agree, viz., the bands of 

 chitine of which the teeth are composed, are all, for 

 a certain portion of their length, turned in on each 

 margin, and thus form a split tube from their point 

 of attachment to about two-thirds of the length of each 

 tooth, when they begin to expand, and continue to do 

 so until the extremity of the tooth is reached. Usually 

 the end presents a V-shape, but there are modifications 

 of this form. 



The illustration represents the position and number 

 of teeth in one lip of the house-fly (Musca domestica). 

 The teeth are six in number, there being three in 

 each lip. The free ends are trifid and serrated ; the 

 two lateral expansions each bear two small saw-like 

 processes, w^hile the central one has seven similar 

 denticulations, the central apex carrying one with 



Fig. 102. — Teeth of the house-fly [Musca domestica], showing 

 position in one lip. 



three on either side, there being eleven denticles or 

 serrations on each tooth. 



In nearly all creatures possessing teeth these organs 

 afford a ready and reliable means of identification ; 

 and after some little study, the outline of which is 

 indicated in these few remarks, I have little doubt the 

 same would apply to this order of insects, and might 

 possibly prove of advantage in determining species 

 apparently slightly removed from each other by 

 outward appearances. 



As an improvement on drying the objects, let me 

 suggest the use of one drop of carbolic acid ; this 

 clears the object and prepares it for mounting in 

 Canada balsam. The whole operation can be com- 

 pleted under five minutes, and a permanent mount 

 secured in every respect equal to one obtained by 

 more lengthened treatment. 



Professor Roscoe, the distinguished chemist, 

 has just received the honour of knighthood. 



