THE ANATOMY 01" THE LEECH. 29 



testes situated posteriorly to it on the same side. In minute structure this body 13 

 precisely the same as the bodies of the testicular series ; like them it is filled with 

 sperm-fluid ; the interior is a cavity. The secreting glandular structure is disposed 

 around the circumference ; the secreted product is thrown into the enclosed 

 hollow. This description applies also in every particular to the other testicular 

 bodies, which are like the former, hollow orbicular glands. The large longitudinal 

 duct which serves as a common channel of communication between all the testes, 

 emerges out of the gland under the character of a duct of greatly reduced size. 

 This small tubular thread, traced with minute care, may be followed into the median 

 glandule to which the penis is appended. In the median line also, and some little 

 distance posteriorly to the body just described, may be remarked a pear-shaped 

 sacculus from the unattached fundus of which a caecal coiled tubule is prolonged. 

 Between this saccular and the other parts of the reproductive system, no communica- 

 tion of any description can be discovered. It seems simply destined to receive the 

 intromittent organ developed in connection with the gland situated in advance of it 

 on the median line. 



It may be inferred from the character of the whole system of the testicular 

 bodies, that the penis is not an ejaculatory organ ; it seems subservient only to the 

 purposes of sexual stimulation. By all anatomists, from the date of the first 

 description of M. Duges, this sacculus has been regarded as an uterus, and as, in 

 fact, constituting the whole of the female element of the generative system. The 

 convoluted caecal tubule pendent from the fundus of this sacculus, including some 

 undiscoverable gland structures on either side of it, are commonly indicated as the 

 ovaria. Such anatomists, whilst entertaining opinions so remote from the truth, 

 and withal so little probable on physiological grounds, never could have seen these 

 parts. An ovarian system so utterly disproportionate to the testicular, if it were 

 true, would find no precedent or parallel in the whole series of invertebrate 

 animals. 



In all hermaphrodite animals the female elements of the generative organs are 

 invariably superior in size, more elaborately organized, and more important as con- 

 stituent parts of the whole organism, than the male: wherefore should the con- 

 veise of this rule obtain in the Annelida ? A cursory glance at the organic neces- 

 sities of the animal system should have sufficed to convince the physiologist that 

 such a simply organized sac, so uncomplicated in structure, so unprovided with 

 8tromatous tissue for the production and development of ova, could not have 

 proved adequate to those profound functions involving in intimate sympathy every 

 other of the organism which are concerned in the continuation of the species. It 

 was the necessity, thus perceived on theoretical grounds, for some series of organs 

 which would reasonably answer to the general characters of a female system, which 

 first led the author to the discovery of that which now remains to be explained. 



In the Leech, the female system consists of a greater number of separate parts 

 than the male, amounting to fifteen or seventeen on either side, while the testicu- 

 lar bodies are only nine. This system is composed of a linear succession of a bag- 

 pipe shape, membranous sacculi, contracting at both ends into two separate ducts_ 

 One of these duits, terminates an orifice communicating externally. It is through 

 this orfice that the ova and young esc ipe from the ovarian utricle into the external 

 medium. In the Leech, the ova in this duct, in every case yet examined, present 

 an obviously greater degree of development than those which are found in the 

 duct which communicates with the neighboring testis. At certain seasons of the 



