ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 401 



papillary fascialc of Riiffmi). The sub-papillary nerve-web composed 

 of medulla-less branches and threads, the uuencapsuled ganglion, the 

 ribbon-form bundles and the intra-papillary network have one and 

 the same source. They represent the end-branchings of the axis- 

 cylinder of those relatively thick medulla-containing fibres which sepa- 

 rate themselves from the bundle of nerve-fibres of the superficial 

 network. The fibres mentioned, after losing the medulla-sheath, break 

 into smaller branches passing not only to one but to several papilla?. 

 A certain number of branches and fibres penetrate the typical (possibly 

 also the modified) Meissner's bodies, and form in the same a more or 

 less close network. Finally, fibres which penetrate the epithelium and 

 end in the same, arise from the aforesaid network and also from the 

 unencapsuled ganglion, from the bundles, and the inter-papillary net- 

 work. 



Olfactory Organ of the Lamprey.* — E. Ballowitz has made a 

 precise study of this interesting organ in Petromyzou fluviatilis, which 

 includes an entrant duct, a complex nasal sac, and a naso-palatal canal 

 which ends just above the oesophagus. He gives an account of the 

 histological peculiarities of the different regions, and corroborates 

 Johannes Muller's observation that the most posterior part acts like 

 an aspiration bladder in a spray-syrinx, being rhythmically compressed 

 and enlarged in association with the respiratory movements. 



Histological Studies on Cerebral Localisation.! — A. W. Campbell 

 seeks to further the establishment of a correlation between function and 

 histological structure, and gives his results on the central gyri, the occipital, 

 temporal, and limbic lobes. The normally existent topographic varia- 

 tions in arrangement of cortical nerve-cells and medullated nerve-fibres 

 have been adopted as a standard criterion in forming judgment on 

 points bearing on localisation. The examination of the disposition of 

 these elements over the entire cortex of human and anthropoid apes' 

 brains, both normal and pathological, constitutes the groundwork of this 

 research, of which the present paper is an abstract. 



Histology of the Light Organs of Photinus marginellus.f — A. B. 

 Townsend finds that the light organs are composed of two distinct layers, 

 lying above the ventral body-wall of the fifth and sixth abdominal 

 segments. The dorsal layer consists of polygonal cells with large nuclei, 

 and with cytoplasm almost entirely replaced by a granular secretion. A 

 similar secretion occurs in the fat-cells of the same region of the body. 

 The ventral layer is composed of two elements, parenchyma cells and 

 cylinders. The former are irregular in shape and size, and their 

 granular secretion is finer than that of the dorsal layer cells, and appears 

 to be different chemically. The cylinders are masses of tissue surround- 

 ing the vertical tracheal ^sterns and their branches. There is no change 

 in the structure of the trachea? until near the periphery of the cylinder, 

 where each fine tracheal twig breaks up into tracheoles. These have no 

 spiral thickening. Photogeny occurs in that portion of the tissue where 



* SB. K. Preuss. Akad. (1904) pp. 671-6. 



t Proc. Eoy. Boo., Ixxii. (1903) pp. 488-92. 



J Amer. Naturalist, xxxviii. (1904) pp. 127-51. 



Aug. 17th, 190 Jf 2 p 



