696 



IIERMAPHRODITISM. 



sionally found unisexual, in consequence of the 

 arrested developement of one order of their 

 sexual organs ; and again, though still more rarely, 

 from an excess of evolution, a double set of 

 male parts, or a double set of stamens, is seen 

 developed on some of the individual flowers. 



In the animal kingdom we find instances of 

 a perfect hermaphroditic structure as the normal 

 form of the sexual type in the Trematodes and 

 Cestoides among the Entozoa, in the abranchial 

 Annelida, in the Planaria, and in many of the 

 Mollusca, particularly in the Pteropoda, and in 

 several families among the Gasteropoda. In 

 some of these animals that are thus naturally 

 hermaphroditic, the fecundation of the female 

 organs of the bisexual individual is accom- 

 plished by its own male organs ; but in others, 

 although the anatomical structure is strictly her- 

 maphroditic, yet the union of two, or, as some- 

 times happens, of more individuals is neces- 

 sary to complete the sexual act ; and during it 

 the female organs of each are respectively im- 

 pregnated by the male organs of the other. 



In the Nematodes and Acanthocephali among 

 the Entozoa, and in the Cephalopoda and Pecti- 

 nibranchiate Gasteropoda among the Mollusca, 

 as well as in all symmetrically formed animals, 

 or, in other words, in those whose bodies are 

 composed of an union of two similar halves, 

 as in Insects, and theArachnida, Crustacea, and 

 Vertebrata, the male and female organs of re- 

 production are placed each upon a different 

 individual of the species, constituting the ba- 

 sis of distinction between the two sexes. In 

 such animals a mixture of more or fewer of 

 the reproductive organs of the two sexes upon 

 the same individual appears occasionally as a 

 result of abnormal formation ; but the male and 

 female organs that coexist in these cases are 

 seldom or never so anatomically perfect as to 

 enable the malformed being to exercise the 

 proper physiological function of either or of 

 both of the two sexes. This form of true her- 

 maphroditism or abnormal mixture upon the 

 same individual of the organs of the two sexes 

 in the higher animals, has been termed unnatu- 

 ral or monstrous, in opposition to the natural 

 hermaphroditism which exists as the normal 

 type of sexual structure in some of the lower 

 orders of animals, and in phanerogamic plants. 

 The malformation itself is observed to differ 

 greatly, both in nature and degree, in different 

 cases, varying from the presence or superaddi- 

 tion of a single organ only of theoppositeor non- 

 predominant sex, up to the development and 

 co-existence of almost all the several parts of 

 the two sexes upon the same individual. In 

 describing the malformation, we shall classify its 

 various and diversified forms under the 

 three general orders pointed out in our table, 

 including, 1st, lateral ; 2dly, transverse ; and 

 3dly, double or vertical hermaphroditism. 



A. Lateral hermaphroditism. According to 

 the opinion of many physiologists of the pre- 

 sent day, the two lateral symmetrical halves of 

 the body, and even the two halves of all its 

 single mesial organs, are originally developed 

 in a great degree independently of one another. 

 Granting this point in the doctrine of eccentric 



developement, we can easily conceive how, in 

 the same embryo, an ovary might be formed on 

 one Wolffian body, and a testicle on the other; 

 or, in other words, how female organs might be 

 developed on one side, and male organs on the 

 other. It is the existence of such an unsymme- 

 trical type of sexual structure upon the two op- 

 posite sides of the body of the same individual, 

 that constitutes the distinctive characteristic of 

 lateral hermaphroditism. 



Instances of this species of true hermaphro- 

 ditic malformation have been observed in many 

 different classes of animals, as well as in the 

 human subject. 



Individual examples are sometimes observed 

 among insects, particularly among the Lepido- 

 ptera, in which all the different parts of the two 

 sides or lateral halves of the body are formed 

 after opposite sexual types. We shall after- 

 wards have occasion to notice different exam- 

 ples of this form of lateral hermaphroditism as 

 seen in the general conformation of the body, 

 but may here state that in two or three in- 

 stances such malformed insects have been care- 

 fully dissected, and found to present, in the ana- 

 tomical structure of their sexual organs, a mix- 

 ture of the organs of the male and female. 



In a MeUtaea didymiu described by King,* 

 the general external characters were those of the 

 male, but the left eye, palpus, and antenna, 

 and the left sexual fang, were smaller than in 

 individuals belonging to this sex; and the left 

 antenna was annulated with white and yellow 

 at the apex, while the right was of one colour. 

 On dissection, the various male sexual parts 

 were present, and they had appended to them 

 a free female ovary situated upon the left, and 

 united to no other organ. 



In a OtatrtnAaga quercifolia dissected by 

 Schultz, and described by Rudolphi.f the left 

 side appeared externally male, and the right 

 female, with a distinct line of separation through- 

 out the whole body. On dissection, Schultz dis- 

 covered an ovarium upon the right side, and 

 two testes upon the left. The oviduct of the 

 ovary joined the canal of the vasa deferentia 

 about two inches before its termination ; and 

 the spermatheca was connected with the com- 

 mon evacuating duct. The two testicles on the 

 left side were placed one behind the other, and 

 connected by a thin vessel. The spermatic 

 duct belonging to one of the testicles imme- 

 diately received, as in the Lepidoptera, the spi- 

 ral vessel ; further beyond, and on the opposite 

 side, a second vessel, which appeared to con- 

 sist of the rudimental spermatic duct of the 

 other testicle, opened into it. The oviduct of 

 the ovary joined the canal of the vasa deferen- 

 tia about two inches before its termination in 

 the penis, and a female spermatheca was con- 

 nected with the common distended evacuating 

 duct.J 



* Froricp's Notizen, vol. x. p. 183. 



t Abhandlung. der Koenig. Akad. zu Berlin fur 

 1825, s. 55. 



t See also drawings of the body and genital or- 

 gans of an hermaphrodite Sphinx populi in Fischer's 

 Oryclographie du Gouvcrncmuut de Moscou (Mos- 

 cow, 1B30.) 



