570 SUMMARY OF CURRENT RESEARCHES RELATING TO 



function, are very largely developed, not only over the whole of the foot, but 

 on other parts of the body ; the contents are almost completely homogeneous 

 and are of a fatty nature ; it is to be noted that Grube has reported that 

 Teihys is remarkable for its strong phosphorescence, and Panceri has 

 remarked that the unicellular glands which serve as the luminous organ of 

 Annelids have fatty contents. 



In another form of gland lamellae are found, some of which exhibit a 

 concentric arrangement, but this may be due to the mode of hardening ; the 

 function of these glands is not quite clear, but it is certain that they are 

 not mucous organs, though it is possible that they are byssus glands, the 

 contents of which have been altered in the process of preparation. The 

 glands with coarsely granular contents are pyriform in shape ; their func- 

 tion is imknown. 



On the lower side of the foot there are, in addition to the goblet-cells, 

 a few small mucous glands, a comparatively small number of luminous 

 organs, and a few scattered glands with granular contents. In addition to 

 these there are specific organs which call to mind the multinuclear colour- 

 and chalk-glands which Leydig has observed in the skin of many 

 terrestrial Gastropoda. They have no surrounding membrane, and the 

 cell-substance generally is a finely granulated mass ; the nuclei are from 

 two to seven in number in each cell, and colour well. They are very easily 

 seen to be connected with connective-tissue cells ; and the author believes 

 that both they and the cells observed by Leydig are only further developed 

 connective-substance cells, which remain in contact with the other cells of 

 the same substance. 



Anatomy of Patella.* — Dr. H. Wegmann contributes some notes on the 

 structure of Patella, an animal often, but only partially studied. His 

 bibliography only comes down to 1883, and the recent thorough research 

 by Mr. E. J. Harvey Gibson has apparently not reached the author. The 

 two systems which are especially discussed are the alimentary and vascular. 

 An Infiisorian parasite found on the gills is also described. As the ground 

 covered by Dr. Wegmann's research is in part included in Gibson's mono- 

 graph, the detailed anatomical results need hardly be summarized. The 

 value of the investigation is increased by the comparison which is in- 

 stituted throughout between Patella and Haliotis, as also by the excellent 

 illustrations. 



MoUuscoida. , 

 a. Tunicata. 



Muscular System of Glossophorum sabulosum.f — M. L. Lahille de- 

 scribes the well-developed muscular system of this Tunicate, which he 

 finds to be very simple and instructive. There are generally six pairs of 

 lateral muscles, corresponding to the six buccal lobes ; occasionally eight 

 pairs — a sign of approximation to the Cionidse which is paralleled by other 

 characters in the organization of Glossophorum — are present. The author 

 remarks, parenthetically, that he is about to demonstrate the homology of 

 what he calls the stolon (pos'-abdomen of Milne-Edwards) with the vessels 

 of the tunic of simple Ascidians, the proliferating stolon of the Salpidse, 

 and the endostylar bud of Pyrosomatidse. Owing to the fact that the ova 

 are always developed on the right side of the rectum, the lateral muscles of 

 the right are shorter than those on the left side of the animal. M. Lahille 

 does not agree with Traustedt that the deviation of the intestine produces 



* Rec. Zool. Suisse, iv. (1887) pp. 269-303 (2 pis.), 

 t Soc. I'Hist. Nat. Toulouse, xx. (1886) pp. 107-116. 



