1826.] FhUosophical Transactions for \%2oy Part II. 213 



centre of the body, and terminates apparently in a cul de sac 

 about the last segment but two of the abdomen." 



Dr. Kidd next describes the muscles and nerves of the gryllo- 

 talpa, the latter arising from a series of nine ganglions; and he 

 gives the following account of the brain. 



" The brain differs in colour from the ganglions, being of a 

 pale brownish pink, instead of a cream colour, and in size it far 

 exceeds the largest of the ganglions. It consists of two hemi- 

 spheres, separated by a fissure, from each of which pass out four 

 processes : the first of these processes unites as above described, 

 with a process from the ninth ganglion, to form the nervous 

 collar of the esophagus ; the second passes to the root of the 

 antenna; the third, which may be called the optic nerve, passes 

 towards the inner surface of the cornea ; and at its extremity 

 swells out into a fringed coronet of an orange red colour ; the 

 fourth process, the extremity of which is also of an orange red 

 colour, proceeds to the ocellus or stemma of the corresponding side. 



" The upper surface of the brain is covered by a mass of soft 

 substance somewhat resembling loose fat." 



The paper is concluded with an account of the generative 

 organs of each sex, some observations on the casting of the skin, 

 and on the organ of sound, and the dimensions of the full-grown 

 mole-cricket. 



" The Sexual Organs of the Female. These organs consist o. 

 two ovaries, which occupy a considerable portion of the upper 

 part of the abdomen, and terminate by a narrow duct in a com- 

 mon cavity or uterus, which opens externally under the posterior 

 edge of the last segment but one of the ventral surface of the 

 abdomen. Behind the uterus is an oblong white body, which, 

 originating from a cul de sac, and then doubhng on itself in the 

 form of a slender tube, terminates in the uterus. The contents 

 of this body resemble a thin white paste. The ovaries are irre- 

 gularly pear-shaped, and consist of a transparent membrane 

 irregularly convoluted, through which the ova, enveloped in a 

 gelatinous medium, are easily distinguished. In the same 

 ovary the ova are frequently of different sizes and colours ; those 

 which are the largest, and which I suppose to be impregnated, 

 are of a brownish yellow colour ; they resist a considerable 

 degree of force before they burst, and the contents when pressed 

 out melt as it were into a soft jelly, leaving a tough membrane 

 which enveloped them. The smaller ova are of various sizes 

 and of nearly a white colour, and of a mucli more slender and 

 compressed form than those which I have supposed to be im- 

 pregnated. This difference in the degree of maturation corre- 

 sponds with a fact stated by Rosel, that the mole-cricket does 

 not deposit all the eggs of the season at one time. In a few 

 instances I found two or three ova which had entered the nar- 

 rowest part of the duct, and were very near the uterus ; and 

 from the appearance of these, which may fairly be supposed to 



