AMERTOAN HOMOPTERA. 363 



readily, and are not horny claws. 2d. That whatever they may be 

 they sustain the weight of the body. I am sure that they sustain the 

 entire weight; no part of the tarsal joint or tibia rests on the slide, 

 and consequently are of greater proportional strength than hairs could be 

 presumed to have ; for two hairs on the sole of each foot would not sup- 

 port the weight of any animal, at least in larger animals where we are 

 better capable of examining hairs and other dermal appendages. We 

 never find hairs thus capable of producing such support. Whoever 

 may think that these organs are hairs, will find them of a different 

 structure", and by such examinations and reflections will see that they 

 are out of all proportion, for hairs, when compared with the minute 

 size of the body itself; moreover, the disks, or suckers, on the extre- 

 mity, is another argument against regarding them as hairs. 



I breathed upon the glass plate, and the precipitated moisture caused 

 the setae of the abdomen to adhere to the slide, and thus prevent the 

 usual rapid locomotion of the insect or retard its progress entirely; but 

 like a good ox it pulls and struggles faithfully, sometimes backing up, 

 taking a fresh start, or turning in the opposite direction ; thus it per- 

 severes perpetually while life lasts. This manipulation gives an excel- 

 lent opportunity to view the tarsal appendages, for it uses every means 

 in its power to aid locomotion, and thereby spreads apart all the organs 

 nature has provided, so that they can all be seen with entire satisfac- 

 tion. 



These methods of examination are infinitely superior to any method 

 of examining the dead specimen, for by no possible contrivance can we 

 manipulate these delicate organs so well as the animal itself, when 

 placed in the proper conditions. 



The anal setse are more than one-half the length of the body, of cap- 

 pilary fineness, and at the distal end so slender as to appear as a fine 

 point under the one-twelfth inch objective. 



Prolonged and repeated observations confirm what has been stated 

 above ; the more I examine the feet, the more I am convinced of the 

 brevity of the tarsal segment. The tarsus here is composed, probably, 

 of but one primitive segment or ring, while the longer tarsal joints of 

 other insects are composed of many, and the tibiae of scores of rings 

 as I have shown in the Froc. Acad. Hat. Sciences, Fhila., Jan. 1867. 



I succeeded in crushing several of these little insects very slightly, 

 just sufiicientto cause them to lie on the side (an operation easier spo- 

 ken of than performed), by which manipulation I saw the four digituli 

 more nearly equal than in any other field of view. The tarsi, there- 



