46 
Psyche 
[June 
face of the head for the same purpose. The cephalic disc 
in old soldiers and in the mother queen of the colony often 
becomes coated with dirt and extraneous particles so that 
it closely resembles the bark of the plant.” 
The most recent note on the phragmosis of Cryptocems 
is that which Kempf published in 1952 (4). Kempf’s single 
observation on Cryptocerus macidatus failed to show the 
behavior cited by Wheeler. It was not until Kempf had 
enlarged the small nest entrance that any majors were 
seen. These majors, which were well inside the nest, then 
tried to occlude the passage which Kempf had opened up 
by standing “side on side”. Kempf recalled that a similar 
compound shield, consisting of the approximated heads of 
several minor workers, was reported for a colony of Ceph- 
alotes atratus by Santschi in 1919 (9). The date of this 
publication is incorrectly given by Kempf as 1929. Kempf 
was clearly aware that neither Santschi’s observation on 
atratus nor his own on maculatus are comparable to 
Wheeler’s statement of the phragmosis of the major of 
pallens. But the writers agree with Kempf that clarifica- 
tion is needed in the case of Wheeler’s 1942 statement. The 
major of Cryptocerus is undoubtedly phragmotic, but it is 
misleading to say that it behaves just as does the Colobop- 
sis major. The notable differences which mark the reac- 
tion of the Cryptocerus major are discussed in the follow- 
ing pages. 
The junior author’s colonies were housed in the modi- 
fied Janet nests used in earlier studies on Pheidole (10). 
These nests gave little opportunity for studying the phrag- 
mosis of texanus, since they lacked restricting passages. 
In order to study this response two other types of nests 
were used, both of very simple construction. The first con- 
sisted of two glass vials with the bottoms removed. These 
vials were held together by a cork, which was forced into 
the neck of each vial until the two rims touched. On one 
side of this cork a groove was cut which approximated the 
size and shape of the cephalic disc of the major as closely 
as possible. The open end of each vial was plugged with 
cotton after the colony was installed. The second type of 
nest was a small, plaster one, cast over a microscope slide. 
