1849.] 235 



factor all organization; for all the innumerable objects of living nature, with 

 such variety of form, connposit ion, and color, from the simplest to the most com- 

 plex: from the vibrionic filament to the noble oak, from the bodo, or monas, 

 up to man, arfe the result of a force in connection with an amorphous 

 vesicle, the organic cell-wall, with the contained nucleus. Wonderful, in- 

 deed, is it that the human mind at length has been enabled to penetrate 

 so deeply into the mysteries of nature as to discover the starting point 

 of life, the stile at which an invisible intangible cause operates in the production 

 of all those beings we call organized. From this digression I return once more 

 to the consideration of the odorifer.ous glands. In many of the higher animals, 

 the structure of thc.?e have been carefully investigated, but riot to the same ex- 

 tent in the lower animals. 



In HemipteroUs insects these bodies arc situated within the posterior part of 

 the metathorax or anterior part of the abdomen, and consist of one or two, more 

 or less long and convoluted coeca, which open exteriorly usually between the 

 coxae of the middle and posterior legs. 



In the carnivorous Coleoptera, they are situated in the posterior part of the 

 abdomen, on each side of the rectum, and usually open exteriorly upon the mem- 

 brane, connecting the inferior and superior plate of the last abdominal segment 

 on each side of the anal aperture. They generally consist of a number of follicles, 

 which converge to one or more ducts, which join the neck of a reservoir for con- 

 taining the secreted fluid. A number of these are figured by Dufour in the An- 

 nales des Sciences Naturellcs for ^S■2<^. 



In the genus of Myriapoda, Julus, the odoriferous glands are placed upon each 

 side of the body, every segment which has a double pair of legs jiossessing a pair 

 of the glands, commencing anteriorly with the sixth segment, excepting the head, 

 and terminating posteriorly with the penultimate segment. As the number of 

 segments of the animal varies with its age, so will also the number of the odori- 

 ferous glands. The adult Julus marginatus has usually fifty pairs, the Julus 

 maximus, from New Grenada, S. A., has fifty-eight pairs, &c. 



The orifices of these glands opening exteriorly, correspond to a row of minute 

 black dots on each side of the body, situated about midway between the superior 

 and inferior median line. 



The glands of Julus consist of a globular body or sac, with an elongated conical 

 neck, and resemble in form a florence flask with the mouth drawn to a point. In 

 Julus marginatus they measure Ij- lines long, the body being I of a line in diame- 

 ter. In structure they consist of an amorphous transparent basement membrane 

 covered upon the interior surface with a single layer of secreting cells. The 

 cells are polygonal, from mutual pressure, measure l-lG12th inch in diameter, 

 and are filled with a yellowish fluid, and a fine purplish granular matter, which 

 in mass gives them a dark purple color, and which, in the aggregate of the cells, 

 gives the glands a very deep purple or almost black color. When the cells are 

 compressed, or the contents pressed out, the granules exhibit lively molecular 

 movement. 



In the centre of the m.ass of granular matter of the cell, and only seen upon 

 compressing the latter, is a round, translucent nucleus, measuring the l-5000th 

 inch in diameter, and containing a minute refractive nucleolus. 



The secreting cells vary in color in different insects, and in the aggregate give 



