EEPEODUCTIVE OKGANS. 517 



organ. The form, colour, and general appearance of these eggless bands 

 do not differ, however, from those charged with ova, and have very 

 much the character of undeveloped ovaries. The generative organs are 

 very perceptibly composed of two elements the yellow ovigerous sub- 

 stance, which forms the chief mass, and a red material, which is distri- 

 buted over the surface of the organ. When the organ is in a low state 

 of development, this red matter forms a narrow irregular cord, which 

 runs along the sides of the band, and is occasionally spread over the 

 surface in spots and blotches. When the ova are mature, this substance 

 can still be traced as small specks on the surface and throughout the 

 mass. From what will shortly be stated in regard to Lingula, it seems 

 probable that this red matter may prove to be the testis. 



(1359.) The minute structure of these organs has not been sufficiently 

 examined ; it may be stated, however, that the ova appear to be de- 

 veloped in cells, and that when the yellow mass which is deficient of 

 eggs is broken up and placed under the microscope, it is found to be 

 composed almost entirely of minute clear granules. The red substance 

 is likewise made up of large irregular cells inclining to oval, very 

 variable in size, and without any apparent nucleus. 



(1360.) In Lingula the reproductive organs are withdrawn altogether 

 from the mantle, and placed in the perivisceral cavity : they are very 

 bulky, occupying a large portion of the chamber ; they lie for the most 

 part behind the liver, and surround the alimentary tube ; they form four 

 irregularly lobulated branched masses, two above and two below the 

 tube ; these pairs may be denominated the dorsal and ventral ovaries. 

 When in a highly developed state, the lobes or branches insinuate them- 

 selves between and around the muscles, so that it is almost impossible to 

 trace the relation of these organs to other parts ; but when immature it 

 is very easy to do so. The dorsal ovaries are then found to be sus- 

 pended by the ilio-parietal bands, the ventral by the continuation of 

 these bands along the pseudo-hearts or oviducts. In both cases the 

 attachment is along the margin of the bands, between the two layers of 

 which they would seem to be developed. In Lingula the red substance 

 alluded to above forms a dendritic or branched organ, spread over the 

 external surface of the ovarian masses. On examining a portion of this 

 branched organ under the microscope, it is found to be composed of 

 large irregular evils, somewhat elliptical in form, and closely resembling 

 those of the red substance in connexion with the ovaries in Waldheimia. 

 The cells, however, in Lingula appeared to present different stages of 

 development, varying much in size and form, and some of them were 

 filled with numerous delicate hair-like bodies resembling spermatozoa. 

 From these facts it can scarcely be doubted that the dendritic organ is 

 the testis, and that the fusiform cells are fully developed spermatophora 

 containing spermatozoids. It would thus appear that Lingula is andro- 

 gynous : and if the red matter in connexion with the generative organs 



