ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 213 



Further, the "fundamental biogenetic law" that the development of the 

 individual is a compressed epitome of the history of the race, cannot be 

 true; the contradictions which all embryologists recognize have been 

 attempted to be explained as cenogenetic, or the results of falsified 

 embryogeny. " Poor logic, hovp- it is tortured ! Nature falsifying herself ! " 



Phylogenetic speculations must, M. Vogt thinks, be completely reversed, 

 and we must recognize that the less complicated animals owe their existence 

 to a more or less complete retrogression, and that they must constitute 

 the final terms and not the foundations of phylogenetic series. It is thought 

 that such paleeontological facts as the presence of Cephalopods and Dipnoids 

 in the most ancient formations squares with the reformed hypothesis here 

 enunciated. 



;8. Histology.* 



Goblet-cells in Amphibian Bladder.f — Dr. J. H. List continuing his 

 researches on goblet-cells, reports their presence in the epithelium of the 

 bladder of Amphibia. The histology of the different layers is minutely 

 described, and the form, size, and structure of the unicellular glands 

 specially discussed. They arise in the deeper layers, undergo the usual 

 modifications, and finally disappear after distinct secretion of their modified 

 mucous contents. The details are corroboratory of List's previous 

 researches. 



Nerves of Electric Fishes. J — Herr Fritsch is of opinion that the fibres 

 of the axis-cylinder in the elements of the central nervous system of electric 

 fishes arise from the fusion of protoplasmic processes. The axis-cylinder 

 begins as a conical protrusion formed from the fusion of broad processes, 

 and penetrated by vessels (Gymnotus, LopJiius piscatorius, Malopterurus 

 electricus. In the ganglion-cells (spinal ganglia) of LopMus, besides the 

 axis-cylinder, fine processes pass through the wall and fuse outside. He 

 thinks it not unjustifiable to conclude that fine processes of the nerve-cells 

 may fuse to form the axis-cylinder, even when their fineness makes 

 demonstration impossible. 



y. G-eneral. § 



Marshall and Hurst's Practical Zoology. || — Prof. A. Milnes Marshall 

 and Mr. 0. H. Hurst have published a ' Junior Course of Practical Zoology,' 

 which ought to be very usefixl to all those who go beyond the work laid 

 down in Huxley and Martin's well-known handbook. The forms dealt with 

 are Amceba, Paramecium aurelia, Vorticella, Hydra, Fasciola hepatica, 

 Hirudo medicinalis, Lumhricus terrestris, Anodonta cygnea, Helix pomatia, 

 Astacus fluviatilis, Periplaneta americana, Amphioxus lanceolatus, Scyllium 

 canicula, Lepus cuniculus, Gallus banJciva, and Golumha livia. This list will 

 show how widely the authors have thrown their net. Valuable explanations 

 will be found here and there among the directions for dissection ; there are 

 forty-eight woodcuts, most of which are original and are among the best 

 and most suggestive that a student, young or old, could have put before 

 him. In an appendix a list of reagents is given, with their mode of 

 preparation and the use to which they are to be put. 



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



t Arch, f. Mikr. Anat., xxis. (1887) pp. 147-56 (1 pi.). 



X Bar. 59 Versammlg. Deutsch. Naturf. u. Aerzte, Berlin, 1886. Cf. Biol. Centralbl., 

 vi, (1887) pp. 735-6. 



§ This section is limited to papers which, while relating to Vertebrata, have a direct 

 or indirect bearing on Invertebrata also. 



II A. Milnes Marshall and 0. H. Hurst, ' A Junior Course of Practical Zoology,' 8vo, 

 London, 1887, 440 pp. (48 figs.). 



