Many Teleostei take care of their progeny, but with the exception of _Aspredo_ and _Solenostoma_, mentioned above (p. 160), it is the male on which this duty devolves. In some, as in _Cottus_, _Gastrosteus_, _Cyclopterus_, _Antennarius_, _Ophiocephalus_, _Callichthys_, the male constructs with more or less skill a nest, and jealously guards the ova deposited in it by the female. The male of some species of _Arius_ carries the ova (Fig. 71) about with him in his capacious pharynx. The species of _Chromis_, inhabiting the sea of Galilee, are said to take care of their ova in the same manner. And, finally, in the Lophobranchs, nature has aided this instinct by the development of a pouch on the abdomen or lower side of the tail. In the Syngnathidæ this pouch is formed by a fold of the skin developed from each side of the trunk and tail, the free margins of the fold being firmly united in the median line, whilst the eggs are being hatched in the inside of the pouch. In _Hippocampus_ the pouch is completely closed, with a narrow anterior opening. [Illustration: Fig. 75.--Syngnathus acus ♂, with sub-caudal pouch.] [Illustration: Fig. 76.--Sub-caudal pouch of Syngnathus acus, with the young, ready to leave the pouch. One side of the membrane of the pouch is pushed aside to admit of a view of its interior. (Natural size.)] The genital organs of _Ganoids_ show similar diversity of structure as those of Teleosteans, but on the whole they approach the Batrachian type. The ovaries are not closed, except in _Lepidosiren_; all Ganoids possess oviducts. In the Sturgeons the oviduct as well as the vas deferens is represented by a funnel-shaped prolongation of the peritoneum, which communicates with the wide ureter. The inner aperture of the funnel is on a level of the middle of the testicle or ovary, the outer within the ureter; and it is a noteworthy fact that only at certain periods of the life of the fish this outer aperture is found to be open,--at other times the peritoneal funnel appears as a closed blind sac within the ureter. The mode of passage of the semen into the funnel is not known. In _Polypterus_ and _Amia_, proper oviducts, with abdominal apertures in about the middle of the abdominal cavity, are developed; they coalesce with the ureters close to the common urogenital aperture.