ZOOLOGY AND BOTANY, MICKOSCOPT, ETC. 737 



In the second part of the essay climbing organs are dealt with ; 

 in the Chrysomelid?e, Hylobiidfe, Telephoridas, and Cerambycidse, 

 the tarsi, in both sexes, are provided on their lower surface with 

 chitinous structures which to the naked eye have the same appearance 

 as those which are found in the males only of the families already 

 discussed. The groups just mentioned live either in water or on 

 leaves or stems, where they move about by means of the tubules 

 covering their tarsi, and by the aid of which they can fix themselves 

 in various ijositions. These chitinous structures are always tubular, 

 and they are never found on more than the first three joints of the 

 tarsi. In tlie tetramerous forms they are widened out and have a 

 distinct orifice, but in the pentamerous Telephoridae they end in a 

 sharp point. In most cases the tubules pour out a secretion, and it is 

 probable that we have here to do with the phenomena not of actual 

 attachment by, as it were, glueing, but of adhesion ; the orifice of the 

 tubes is directed obliquely, and the tubes are, at this point, extremely 

 delicate and flexible, so as to adhere by their lower surface ; in this 

 adhesion they are aided by the secreted fluid. 



In the Cerambycidfe there is no secretion, and the tubules are 

 merely sucking organs, analogous to those which are found in the 

 male Sil])hid£e. 



Discussing the Diptera, observations on which have been made by 

 a number of naturalists whose results are here compared, the author 

 describes the ordinary arrangement (such as is seen, for example, in 

 the common house-fly) as consisting of two attaching lobes; between 

 these there is a rod-shaped elongated piece, beset with chitinous 

 hairs. He does not accept the theory by which the movement of the 

 fly along smooth surfaces is ascribed to an alternate fixation and 

 separation, but believes in a process of adhesion, aided by a secretion, 

 just as in the case of the Coleoptera. The attaching lobes closely 

 beset with chitinous hairs are enabled, in consequence of the pressure 

 of the foot, to completely lie along any smooth surface ; this expels 

 the air beneath the lobes, which are then acted on by the pressure of 

 the outer air. 



There are a few observations on the Hemiptera, Neuroptera, 

 Lepidoptera, Hymenoptcra, Orthoptera, and Strepsiptera ; and, in 

 conclusion, analogous cases are cited from other divisions of the 

 animal kingdom ; sucking tubes are seen in the Acinetae, ambulacral 

 feet in Echinids and Asterids, sucking organs of attachment in Chiton 

 and Patella, suckers in the Cestoda and the Hirudinea ; Schmidt 

 regards the pectines of the scorpion as having a similar function^ 

 and numerous examples are to be found among Vertebrates. 



Locomotion of Insects on Smooth Surfaces.* — Dr. J. E. Eom- 

 bouts writes as follows : — 



" I have concluded from my experiments that it is not the pressure 

 of the air nor the power of an adhesive liquid that gives flies the 

 faculty of running over smooth bodies, but that the power should be 



• Amer. Jlon. Micr. Journ., v. (1884) pp. 99-100. From Pop. Sci. Mou.» 

 May 1884. 



