OF THE SPHINX LIGUSTRI. 
387 
cerebral lobes there are also two minute pairs which form very remarkable 
ganglia, similar to those described by Straus Durckheim in his Anatomy 
of the Melolontha. These ganglia I have ventured to call anterior lateral 
ganglia. The two pairs of nerves originate, one from the base of the nerve to 
the antennae, the other from the posterior surface of each lobe, [PI. XII. and 
XIII. fig. 2. (a, c).] They are directed backwards and outwards, and after 
passing for some distance unite and form an irregular lunated ganglion, which 
is closely connected to another of an oval form. Both these ganglia distribute 
filaments to the muscles of the neck and to a lateral branch of the dorsal 
vessel, and are connected with a system of nerves derived from the large gan¬ 
glion in the second segment, [PI. XIII. fig. 2. ( a , c, i).] 
All the nerves which supply the organs of motion belonging to the head and 
mouth, excepting only those to the antennae, derive their origin from the first 
ganglion. There are four distinct pairs; three of which proceed from the 
anterior, and one from the lateral surface of the ganglion. The largest pair 
from the anterior surface are divided into three branches, and go directly to 
the mandibles [Plate XIII. fig. 2, (b, &)] ; the next to the palpiform spinnerets 
[fig. 2. ( d , d)] ; and the third apparently to the inferior lip ; while the lateral 
pair [fig. 2. (c, c)] are given exclusively to the silk-bags, which afterwards are 
the salivary vessels of the perfect insect. 
Nerves of the Thorax. —These arise from the second, third, fourth and fifth 
ganglia, and their intervening cords, [Plate XII. and XIII. fig. 1. (2, 3, 4, 5).] 
The first pair from the second ganglion are remarkably small in the larva, 
and their distribution is not easily traced. The second are large, directed 
forwards, and divided into many branches, which supply the muscles of the 
head and neck, [fig. 1. (c, c).] The third are carried backwards for a little 
distance, and then turning forwards enter the first pair of legs, [fig. 1. ( d , r/).] 
Both the cords between the second and third ganglia produce a single nerve, 
which is directed backwards, and unites at an angle with the first nerve from 
the third ganglion, [fig. 1. (/,/).] These form a single trunk, which goes to 
the first pair of wings in the perfect insect. It is now of small diameter, but 
is carried forwards and distributes filaments among the muscles at the anterior 
part of the segment. This trunk is also connected with a system of nerves of 
which we shall speak more particularly hereafter. The second pair from the 
