ZOOLOGY AND BOTANY^ MICEOSCOPY, ETC. 635 



The best method of making sections through the eye of Musca 

 I'omitoria is to expose it to the fumes of 1 per cent, osmic acid 

 solution for 40 minutes, then to wash for a few minutes in 60 per 

 cent, spirit, and finally to harden in absolute alcohol. When the 

 hardness of the chitin prevents the use of the automatic microtome, a 

 Jung's microtome with the razor set so as to give a long sweep at each 

 stroke may be used. The best method of depigmenting the eye, is 

 to expose the sections to the action of nitrous fumes ; for teasing the 

 best solution is chloral hydrate. 



Tracks of Insects resembling the Impressions of Plants.* — M. 

 E. Zeiller describes the burrows made by Gryllotalpa vulgaris in the 

 clay soil at the bottom of a little pool of water, that was sometimes 

 nearly dry. These tracks, owing to their arrangement and the marks 

 made on their surface by the insect in traversing its burrow, bear a 

 striking resemblance to the impressions of certain fossil plants. 

 They suggest a comparison with Pkymatodcrma Uasicum and present 

 at the same time an analogy to certain impressions of conifers 

 belonging to the genus BrachyphyUum, notably B. Desnoycrsi Brgt. 

 from the oolite. 



Morphology of the Lepidoptera.t — Dr. A. Walter finds that the 

 views of Savigny as to the morphology of the gnathites of the Lepi- 

 doptera must now be definitely given up ; the parts which he re- 

 garded as mandibles are the projecting angles of a labrum, and the 

 plate which he regarded as the labrum is an epipharynx. True and 

 functional mandibles in the form of toothed appendages are found 

 only in some of the lower Micropteryginfe, such as Aruncella, and 

 Anderschella. True mandibles without denticulations are to be found 

 in the higher Micropteryginae, such as Micropteryx, Purpurella, and 

 Semipurpurella. Various stages of reduction are to be observed in 

 various forms, and it is possible that remnants of mandibles are to be 

 made out in all the ' Microlepidoptera. There can be no doubt that 

 the lower Micropteryginae exhibit the most primitive form of gnathites 

 found among the Lepidoptera. 



There are two maxillary palps, the outer of which forms the most 

 primitive rudiments of a proboscis, while the inner forms a groove- 

 like horny plate which afibrds a lateral support for the labium. The 

 Lepidopterous proboscis is to be regarded as being primitively 

 derived from the outer palp of the maxilla ; in the higher forms the 

 inner palps are reduced. 



In the lower Micropteryginoe the labium has the free palps and 

 typical ligula of lower insects, the latter being formed by the fusion 

 of the inner palps into a short tubule, which is open externally ; a 

 short hypopharynx is to be detected on the soft inner or hinder wall 

 of tliis ligula. 



In the higher Micropteryginas the mandibles lose their teeth, and 

 the maxillso the inner palp ; the halves of the i)robosci8 are applied to 



♦ Bull. Soc. Geol. Franco, xii. p. C76, See trnnsl. by Prof. J. F. James in 

 Journ. Cincinnati Soc. Nat. Hist., viii. (1885) pp. 49-52. 



t JcnaiBch. ZcitBchr. f. NaturwiaH., xviii. (1885) pp. 751-807 (2 pla.). 



