PSYCHE 
VOL. XXXIV. APRIL 1927 
No. 2 
THE THORACIC SCLERITES AND WING BASES OF THE 
ROACH PERI PLAN ETA AMERICANA AND 
THE BASAL STRUCTURES OF THE 
WINGS OF INSECTS 
By G. C. Crampton, Ph. D. 
Massachusetts Agricultural College, Amherst, Mass. 
The head and abdominal structures of the American roach 
have been described in Vol. 32, p. 195 of Psyche for 1925. In 
the present paper the thoracic sclerites and wing bases of the 
roach are discussed, and certain previously overlooked struc- 
tures in the basal region of the wings of insects in general are 
described, since they appear to be of considerable interest from 
the standpoint of phjdogeny and the interpretation of the wing- 
veins 
In examining the thoracic sclerites, it is preferable to study 
them in relation to the internal structures for muscle attach- 
ment, etc., and with this purpose in view, the dorsal (or the 
ventral) region of the thorax should be cut away, and the parts 
should be boiled in 10% caustic potash to remove the muscles 
and other soft parts, which may be washed away with a pipette. 
The parts should be studied immersed under water or alcohol, 
and the field of the binocular should be illuminated by a brilliant 
light provided with a bulls-eye condenser. 
The neck (“cervicum” or eucervix) is a demarked anterior 
portion of the prothorax, whose membranous walls permit 
greater freedom of movement for the head. Its sclerites, called 
the cervical sclerites (cervicalia) are homologous with the in- 
tersegment al plates (intersegmentalia) occurring between the 
thoracic segments in certain Apterygota, and, according to their 
position, they are called the dorsal, lateral and ventral cervicals. 
