WINGLESS REPRODUCTIVE TYPE OF TERMITES 597 
two fairly distinct types, one with brain and sex organs of normal 
size, nymphs of the first.form; the other with these organs 
slightly smaller, nymphs of the second form. The longer and 
shorter wing pads of the two forms are first visible when the 
nymphs have attained a body length of about 4mm. 
The characteristic external features of a nearly mature nymph 
of the first form, about 6 mm. long (fig. 1), are the rounded head, 
tapering slightly toward the posterior end, the prominent light 
brownish or pinkish compound eyes, and the long wing pads 
which extend backward as far as the fifth abdominal segment. 
The number of antennal segments is eighteen. The abdomen 
is more slender than in the second-form nymph of similar age, 
the same is true of the legs. On the ventral surface of the ninth 
abdominal segment, in both sexes, two genital appendices are 
present. 
Internally, as seen from stained whole mounts and sections, 
the brain is the largest of any of the castes, with the most highly 
developed mushroom bodies, and the largest optic lobes in corre- 
lation with the largest compound eyes. The frontal gland is 
also the largest and is acquiring a glandular structure (Thompson, 
16). The venation of the long slender wing pads is similar to 
that of the adult. The abdomen is slightly swollen, the sex 
organs are fully formed, but are not as near the functioning period 
as those of the second-form nymph. In the female (figs. 1, 21), 
the ovaries are long and slender, extending the entire length of 
the abdomen, but the contained ova are not yet greatly enlarged. 
The seminal receptacle is fully formed, the oviducts and the 
vaginal duct are united and have a visible lumen. ‘The colleterial 
gland is large and convoluted. In the male (fig. 24), the testes 
are large, with many lobes, the vasa deferentia have a lumen, 
and the seminal vesicles are elongated and convoluted. Posterior 
to their junction with the seminal vesicles the vasa deferentia 
continue as a single ejaculatory duct which ends in a muscular 
and evidently protrusible penis, enclosed in a sheath. As in all 
reproductive forms the space between the epidermal layer and 
the body organs is filled with masses of fatty tissue. 
