ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 35 



Organs of Aquatic Locomotion.* — Dr. P. C. Amans examines the 

 characters of the organs of aquatic locomotion. He finds that there are 

 two great groups of them, erectile machines, in which the vascular and 

 connective systems play the principal part, and articulated machines 

 formed chiefly of solid levers and muscles. The external form is that 

 of a more or less elongated ovoid having a bilateral symmetry ; the 

 profile, which is the intersection of the surface by the plane of bilateral 

 symmetry, is always itself asymmetrical ; there may be an inflexion in 

 the upper half as in some fishes, or in the lower half, as in Pterotrachea, 

 Dytiscus, &c. The mechanical laws of swimming are discussed at great 

 length, and a further essay is promised in which other factors of rapidly- 

 moving bodies will be considered. 



Zoology of Victoria f— The sixteenth decade of Prof. F. M. M'Coy's 

 Prodromus of the Zoology of Victoria contains accounts of Polyzoa by 

 Mr. P. H. M'Gillivray, and of Crustaceans by himself. The Polyzoa 

 are Lagenipora tuherculata and L. nitens, which, in the author's opinion, 

 ought not to be placed in the same genus. Lehythopora liystrix has its 

 peristome produced into a long, nearly cylindrical tube. In Pcecilojpora 

 anomala the mouth is so reversed that the ooecium appears to be below 

 it. Four species of Fasciculipora — F. gracilis, F. hellis, F. fruticosa, 

 and F. ramosa, are described and figured, as are also Farciminaria 

 aculeata, F. uncinata, F. simplex, and the apparently common Brace- 

 hridgia pyriformis. Palinurus Hugeli, the Sydney crawfish or spiny 

 lobster, is, for the first time, figured in its natural colours. The Yarra 

 spiny crayfish is a variety of Shaw's Astacopsis serratus of the Murray ; 

 it is usually less than half the size of the Murray individuals, while the 

 whole thorax and abdomen also are of an intense prussian-blue 

 colour. 



j8. Histology.J 



structure of Muscle. § — Dr. A. EoUett reports the results of his 

 investigation of the fin-muscles of the sea-horse, and discusses striped 

 muscle in general. The muscle of the fin of Hippocampus antiquorum 

 is first described ; Eanvier's description is rejected as incorrect, 

 EoUett's previously published views are confirmed. The sarcolemma is 

 widely separated from the fibrils by a granular mass — the "sarco- 

 plasma," which is coloured red in gold'staining, and left pale when the 

 fibrils are stained with hsematoxylin. The transverse sections, of 

 which large figures are given, show numerous arrangements of Cohnheim's 

 areas into bands and circles, clearly marked and separated by wide 

 spaces of sarcoplasma. In insects and crustaceans the areas were 

 variously disposed, and much less sarcoplasma was present* The 

 optical longitudinal sections of Hippocampus muscle have the usual 

 appearance, except that wide bands of sarcoplasma intervene between 

 the fibres and even fibrils. The dots and the transverse striae are 

 sections of the walls of sarcoplasma separating both fibres and fibrils. 

 The sarcoplasma is to the muscle-elements as the wax honeycomb to the 

 honey. Eollett gives full particulars of his various methods, materials, 

 and results, and also describes the appearances seen by using the 



* Ann. Sci. Nat., vi. (1888) pp. 1-164 (6 pis.). 



t ' Prodromus of the Zoology of Victoria,' xvi. (1888). 



j This section is limited to papers relating to Cells and Fibres. 



§ Arch. f. Mikr. Anat,, xxxii. (1888) pp. 232-66 (2 pis.). 



D 2 



