PKOGRESS OF MICROSCOPICAL SCIENCE. 33 



stems, run within the Saftcanale between the bundles of connective 

 tissue. 



3. A thick net of non-medullated nuclei containing nerve-fibres is 

 distributed in the mucous membrane of the oesophagus of the frog. 

 From this net, fine nerve-fibres branch off and ascend vertically in the 

 direction of the epithelium, and can be followed to the interstices 

 between the epithelial cells. 



4. The nerve-fibres of the mucous membrane of the stomach and 

 intestine of the frog arise from nerve bimdles, which often pierce the 

 muscular coat in company with small arteries. In their further 

 course, two principal directions are to be made out. Part of the fibres 

 ascend vertically from the deeper layers of the mucous membrane and 

 reach the epithelium of the mucous layer. In this course, they give 

 fine threads to the gastric and intestinal glands. A connection 

 between, the nerve-threads and the epithelial structures could nowhere 

 be made out. The other part of the nerve-fibres of the mucous mem- 

 brane ascend at first in the form of an arch, and later have a dii-ection 

 parallel to the surface of the mucous membrane. In that the above- 

 named bondings occur at different heights, so that on a vertical section 

 there appear three or four parallel rows of nerve-fibres. These nerve- 

 fibres are destined for the capillary vessels of the mucous membrane, 

 and form, on making sections parallel to the surface, long drawn-out 

 nets around the blood-vessels ; single nerve-threads touch in, a 

 radiating manner the walls of the capillaries. 



Is Dichcena rugosa a Lichen or Fungus ? — This subject is very well 

 discxxssed in a pajier by Mr. F. C. S. Roper, F.L.S., which was lately 

 read before the Eastbourne Natural History Society. After some 

 introductory remarks, the author said the w'hole surface of the patch 

 when viewed with a low power is granular or minutely tubercular, of 

 a dull browmish-black colour, and in some cases tinged here and there 

 with green. On making a section, it is foiuid that these granular 

 bodies arise from below the cuticle of the bark, but without any trace 

 of mycelium penetrating the bark itself, as is commonly the case with 

 Fungi ; they are of irregular outline, and enclose a cavity, opening by 

 a pore, or rather slit, at the summit. This cavity is more or less 

 filled with asci, or small sac-like bodies, which contain spores, sur- 

 rounded with a mass of filaments called paraphyses, which are septate 

 or jointed, and curiously bent or hooked at the summit. The number 

 of spores in each ascus is variable, generally from two to six, though 

 as the spores are large, it is not improbable that the normal number is 

 eight. The spores are oval, and the largest about -j-j/ij^th of an inch 

 in length ; they are filled with granular matter, of a pale brownish 

 tinge, variegated by a mixture of bluish green. These spores, w^hen 

 mature, escape through the aperture at the summit of the gi-anules. 

 Scattered over the edges, and at times imbedded between the plants, 

 we find masses of green bodies (Gonidia), which are very minute, 

 varying in shape from distinct circles to ovals or oblongs, encircled 

 by a hyaline or transparent border wdth a double-cell wall. The green 

 matter in the smaller of these bodies (which is probably chlorophyll) 

 is homogeneous. In the larger we find segmentation commenced, and 



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