TRACHEATA 329 
of breathing, and the consequent absence of a respiratory 
function of the blood, has taken place concurrently with the 
formation of a new method of ridding the body of its waste 
nitrogenous matter. In most other Coelomata this is effected 
either by means of tubules ultimately ending in flame cells, or 
by nephridia, and these two methods are connected by inter- 
mediate forms; but in the true Tracheata the nitrogenous 
matter leaves the body by caecal diverticula of the alimentary 
canal, formed usually from the proctodaeum, but sometimes 
from the mesenteron. These Malpighian tubules receive the 
matter they are to excrete either at first hand from the blood, 
or the urates, etc., have been stored for a time in the cells of a 
mesoblastic tissue, the fat-bodies, and, when these disintegrate, 
the nitrogenous matter is carried by the blood to the tubules, 
and thence passes through the rectum to the exterior. 
The nervous system of Jelolontha is very concentrated, 
instead of the double nerve cord enlarging into a ganglionic 
wes Ge ws 
soup ----8 Fre. 188.—View of nervous system of Melolontha 
| vulgaris. After Vogt and Yung. 
. Cerebral ganglion. 
2. Sub-oesophageal ganglion. 
. Ist thoracic ganglion. 
\ 
= 
SS 
== » 
—— 
' 
\ v 
' 
' 
' 
H 
Oo 
oO fF WwW WY He 
ae — . 2nd thoracic ganglion. 
| 1 
Aili | Ke ak . ord thoracic ganglion. 
Zi ih ee ; : 
2 || Mi aN 6. Fused abdominal ganglia. 
Ui —— FH | — { N = 
Hi = | 7. Nerves to antennae. 
—7) |) WW NW 
=e] = | 8. Optic nerves. 
5 | ee See - ; 
= f Ss --10 9. Origin of sympathetic nerves. 
. Abdominal nerves, a pair to each segment, 
; which split into an anterior and posterior 
y | branch. 
UM 
mele 
oe 
mass in each segment, the ganglia are to a great extent fused 
into a central mass, from which the nerves radiate. 
The supra-oesophageal ganglion occupies a considerable part 
of the head; it consists of two well-marked lobes separated by 
