ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 199 



of the agency that, causes the heemoglobin of some animals to unite with 

 a certain amount of water of crystallization, and that of other animals 

 with a different amount. But the author's recrystallization experiments 

 seem to make it certain that some such substance or agency does exist. 



B. INVERTEBRATA. 



Parasites of Teredo navalis.* — Mr. W. F. Durand gives a brief and 

 not technical account of the four parasites found by him in [region not 

 stated] Teredo navalis; one appears to be allied to Trichonympha agilis, 

 two others are probably Protozoa, and the last mentioned " has much 

 the appearance of a nematoid worm." These " imperfect results of the 

 first observations are given as a hint where a comparatively little worked 

 field of examination may be found." 



Fauna of Mosses.f — Dr. 0. E. Imhof, excited by the work of 

 Zelinka on the Callidinidje, which live symbiotically with Hepaticae, 

 has examined various mosses. He has found a rich fauna made up of 

 Rhizopods, Flagellates, Ciliate Infusoria, Eotifers, Anguilluliclas, Acarina, 

 Arctiscoidea, and insect-larvse. 



Mollusca. 



Microscopic Structure of Muscles of Molluscs.} — Prof. H. Fol has 

 directed his attention to the minute structure of the muscles of the 

 Mollusca, as to which so little is certainly known. Notwithstanding 

 the statements of various histologists, he has convinced himself that there 

 is no true transverse striation in any mollusc. All the phenomena 

 which have been explained as due to such striation are really caused by 

 the spiral fibrils which surround the smooth fibres. The spiral turn 

 varies in length with the number of fibrils, and with the state of con- 

 traction or relaxation of the fibre ; in the mixture of glycerin and nitric 

 acid used by Paneth the contraction is so great that the parts of the 

 spire become almost transverse ; and this fact explains the error of this 

 writer. 



Ingestion of Water in Lamellibranchs, Gastropods, and Pteropods.§ 

 — Dr. P. Schiemenz comes to the conclusion that those authors who, like 

 Kollmann, Griesbach, and others, have asserted that there are Mollusca 

 which can take in water by means of pores or clefts are correct ; but, on 

 the other hand, the animals in which they believe that they have demon- 

 strated these orifices have not got them, and the water-pores they have 

 described have no existence. He also brings forward evidence to show 

 the existence of intercellular spaces ; these are connected with the sur- 

 rounding medium, but terminate in closed tips; they have nothing to 

 do with the epithelial cells, as they are only evaginations of the basilar 

 membrane. Delle Chiaje and his school were right in supposing the 

 existence of a water-vascular system distinct from the blood-vascular, 

 although such is not to be found in a number of molluscs in which they 

 believed it to be present. Molluscs which have no closed blood-vascular 

 system in the foot — such as Pteropods, Heteropods, Pulmonates, and, 



* Amer. Mon. Micr. Journ., viii. (1887) pp. 224-6. 



f Zool. Anzeig., xi. (1888) pp. 39-40. 



X Comptes Kendus, cvi. (1888) pp. 30G-8. 



§ JIT. Zool. Stat. Neapel, vii. (1887) pp. 423-72 (2 pis.). 



