2 Transactions of the Society. 



interest to microscopical observers. To give an account of tlie 

 diatoms only among the many constituents of this mud it would 

 be necessary to recount the numerous memoirs published upon this 

 important and highly interesting class of organisms from the time 

 of Ehrenberg. I would venture to direct attention to the observa- 



Plate II. 



Fig. 4. — Bodies found in mud from Barking Outfall. — a, fragments of muscular 

 fibre, partly dissolved by the action of the digestive fluids. The specimen on the 

 left still retains its transverse striae very distinctly, c, portion of spiral fibre of 

 vegetable tissue, free from membrane. /, fine fibres of yellow elastic tissue, pro- 

 bably from areolar tissue of meat taken as food, h, portion of yellow fsecal 

 matter undergoing disintegrative change. 



In the following figures in plate II. objects found in mud from a sewer close to 

 Woolwich Pier are represented. — Fig. 5, fragments of deal wood. Fig. 6, a, mus- 

 cular fibres exhibiting transverse strise very distinctly, with the exception of 

 one, a, in the lower part of the figure to the right, which is a representation of a 

 very small fragment partly dissolved, d, crystals, probably of fatty acids, set free 

 by the decomposition of fatty matter, e, sporules of fungi. /, fibres of yellow 

 elastic tissue, g, a collection of granules, probably altered fsecal matter. Fig. 7, 

 a, fragments of muscular fibres in various states of disintegration. Fig. 8, c, 

 spiral fibres from vegetable tissue ; the lower figure represents a portion of a fibre 

 set quite free from its enveloping membrane. 



Plate III. 



From an outfall of a sewer near to Trinity Ballast Office. — Fig. 9, a, muscular 

 fibres acted upon by the juices of the alimentary canal in much the same condi- 

 tion as when they left the body with the fsecal matter to pass into the sewer. 

 Fig. 10, d, free crystals of fatty acids resulting from the decomposition of fatty 

 matter. Fig. 11, c, spiral fibres from vegetable tissue. Fig. 12, a, muscular 

 fibres partly acted upon and disintegrated, h, epidermis from a leaf. 



From a mud-hank off Fast Greenwich. — Fig. 13, a*, muscular fibre partly dis- 

 solved but still showing a few transverse markings, d, crystals of fatty matter 

 with some fsecal matter. Fig. 14, d, fragments of white fibrous tissue, much 

 decomposed and rendered granular by the action of the water and disintegi-ating 

 agencies. /, portion of thick yellow elastic tissue from the coat of a large aitery. 

 Fig. 15, h, portions of stercoraceous matter with granules and oil-globules im- 

 bedded in them. 



Plate IV. 



From a mudbank off Fast Greenwich. — Fig. 10, o, fragments of coal, r, epithelial 

 cells, probably from the mouth. Fig. 11, very fine fibres of yellow elastic tissue. 



From a mudbank at Chelsea. — Fig. 12, a, muscular fibre much disintegrated. 

 h, masses of yellow fsecal matter undergoing disintegration by the action of the water. 



From an outfall of a sewer near to Trinity Ballast Office. — Fig. 13, c, fiagments of 

 spiral vessels from vegetable tissue, d, crystals of fatty acids set free by the 

 decomposition of fatty matter. A collection of the same is represented in Fig. 14 

 at d. e, sporules of fungi. /, fibres of yellow elastic tissue, many exhibiting 

 transverse markings produced by boiling old fibres. 



From a mudbank at Chelsea. — Fig. 14, c, vegetable cells with spiral fibres. 

 Fig. 15, s, a portion of cellular tissue from some vegetable, probably turnip. 

 Fig. 16, p, fragment of white fibrous tissue much disintegrated and with nume- 

 rous granules therein, a*, a portion of muscular fibre nearly transparent from 

 maceration, but a few transverse markings still remain distinct. /, a small frag- 

 ment of yellow elastic tissue showing vestiges of transverse markings, o, frag- 

 ment of coal. Fig. 17, a, portion of muscular fibre changed by maceration, o, frag- 

 ment of coal. Fig. 18, o, fragments of coal. Fig. 19, portion of a very large mass 

 of fsecal matter containing many silicious and other fragments imbedded in it, 

 and which adhere to the viscid matter of which it is in great part composed. 



