MR. TUFFEN WEST 
113 
der of the membranous expansion. In the function they perform, these rays may be aptly 
compared to the ribs of an umbrella. In the large suckers they are rery strongly 
marked ; in the smaller, which are only 2^0 inch in diameter, they are but faintly to be 
traced. An interesting indication of bilateral symmetry may be observed in both the 
great suckers. These are freely and to a great extent moveable on their very short 
membranous pedicles. The mode of attachment of the small suckers to their pedicles, 
by means of a very narrow tendinous cord, is also such as to admit of free motion (fig. 36). 
It will be seen, on reflection, that much power of adaptation to varying surfaces will thus 
be gained*. The pedicles of the smaller are strong, horny columns, -005 inch in length ; 
•0007 inch in thickness at the centre ; they expand a little towards either end, the lower 
or outer being the larger. 
The pedicles of the small suckers were found so closely to agree with the description 
already quoted of the structure of true insect hairs, that it is unnecessary to describe it 
or do more than refer to the figures given of it and of the base of one of the fi 
"guard-hairs" (figs. 37, 38) 
o" 1 ^ & 
that 
There was hence no resisting the remarkable and unlooked-for conclusion, 
suckers of the male Dyticus are extreme modifications, in one direction, of true hairs for 
holding purposes— that therefore they must be classed with all modifications of bans, 
however different in external appearance, for similar purposes. 
It is curious to observe how a truth, when once obtained, receives support from all other 
truths with which it may be connected. It occurred to me to examine, m connexion mth 
this part of my subject, the singular hand of the male Hydrophilm (fig. 10, PL XLIII ), 
which is entirely for sexual purposes-so much so that the insect walks on the end of th 
tibia alone, and drags the tarsus after it. This portion of the limb has the usual number 
of five joints, the last of which is alone enlarged into the form of an irregular hollow 
shield. On the under surface of this shield are a few true hairs, not spmes, as the papilla 
on which they are seated and the articulation at their points of attachment to these 
papillae distinctly show. The longest of these bans are proximal ; they are aU pointed, 
and appear loose! ill-formed, and, as it were, togged backwards Yet this -^J» 
ably represents the hand of Dyt«mt-## last the most completely suctorial organ of its 
kind we are acquainted with. . %i mmmm s tm u + n 
I now come to mention briefly the subject of tcnent bans spee.ally subsc. to 
climbing or holding, as distinct from sexual purposes. None ol these are B^* 
most of °the appendfges which have been hitherto *^ J* ^£££5 
in the shafts, generally very numerous, and horny almost to tnc \ery up, 
membranous expansion suddenly commences. The remarkable bending downwards near 
the tips attains its maximum amongst the tenent ^^ jS^. 8characterUtic 
Clytns ehngatus, one of the Ceranibycidse (fig. 41, PI- JLLiii-1. rain 
examplet. JJter the minute descriptions which haye been already giycn of se, cial fo ms 
* 
swimming about with 
its hands. , - . d 5econ a being dilated, 
t " The tarsi" of the Longicomes « have the three basal joints cushioned bene. th the fi ^™*f ° 
e third deenlv bilobed. the fourth small and nodose and inserted between the lobes of the thud, and 
and slender."— West wood, Introd 
3K2 
