CONSTITUTION AND DEVELOPMENT OF TERMITES. 3808 
The well-known law of Fritz Miller as to the increase in the 
number of antennal joints is certainly inaccurate for Termes 
lucifugus. 
The 11-jointed antenna acquires its 12th joint by subequal 
division of the 38rd, so that it cannot be said whether the 
resulting 3rd or 4th is the younger. When the number of 
joints exceeds twelve it is an indisputable rule that the third 
is the youngest if the number is odd, and the fourth if the 
number is equal. And when the number of joints is odd no 
fresh joint develops until its predecessor has become pilose ; 
for I have never found an example with an odd number of 
joints which were all pilose, while it is easy to find examples 
with an equal number of joints which are or are not all pilose 
(Pl. 17, figs. 28—37). 
I shall now describe the substitute and complementary royal 
forms somewhat fully. 
They rarely exceed 11 mm. in length, and those without 
trace of wings probably never attain a length of more than 
6 or 7mm. The only two kings I have found measured about 
7 mm. in length. The shape both of the head and thorax in 
the examples possessing wing-rudiments is exactly similar to 
that of the nymph, and therefore of the perfect insect. On the 
other hand, those which have no sign of wings find their 
parallel in the small-headed larve; their pronotum has a 
characteristic shape, which will be better understood from the 
figure than from a laborious description, and which distin- 
guishes them from the workers without a shadow of un- 
certainty (Pl. 17, figs. 26, 27). 
The colour of the body, as before mentioned, is generally of 
the pale yellow tone of old paper, sometimes with an aureous 
tinge. The head is dull aureous-yellow, with brown com- 
pound eyes, which are wanting, as I have said, in the com- 
pletely wingless forms. Many old examples exhibit large 
areas which appear brown or sepia-coloured to the naked eye, 
but are seen under the microscope to be yellow sprinkled with 
minute black spots. These areas are as follows: 
