158 Miscellaneous. 



tionary, but the two pairs of hooks move backwards, the base 

 remaining stationary whilst the apex describes a quarter of a circle. 

 They stop when they form a right angle with the central styles. 

 After a moment's repose, the embryo contracts itself, and the hooks 

 return to their original position. The same operation is continued 

 for hours, and in this manner the worm penetrates into the tissues 

 by means of the two central styles, and the two pairs taking their 

 point of support in front, tear a passage for the entire embryo. If 

 we bear in mind that these embryos scarcely exceed the size of the 

 blood-discs of the frog, we may easily understand that they can 

 perforate the intestine to encyst themselves under the peritoneum, or 

 penetrate into the vessels, so as to be carried with the blood into the 

 various viscera, not excepting either the brain or the eyes. 



The question remaining for solution is that of the transformation 

 of the embryo with six hooks into a Cysticercus ; is this effected by 

 metamorphosis, or by germination, as has recently been advanced? 

 There are Cistoid worms, in which, according to my observations, this 

 transition evidently takes place by metamorphosis, that is to say, the 

 first embryo becomes a Cysticercus ; in other cases, if Stein's state- 

 ments be correct, the embryo produces the Cysticercus. In other 

 words, the Scolex is born of a Proscolex. — Comptes Rendus, Novem- 

 ber 21st, 1853, p. 788. 



Further Observations on the Animal Substance analogous to Vegetable 

 Cellulose. By M. Virchow. 



In a previous note*, I announced to the Academy the discovery 

 of a peculiar substance in the brain and spinal cord of man, which 

 gives rise to the same chemical reactions as vegetable cellulose. 



Wishing to follow out this discovery, I sought for the new sub- 

 stance in most of the tissues of the human body, both in a healthy 

 and morbid condition, but in vain, until it occurred to me again in a 

 rare disease, an affection of the human spleen, which commences 

 by a nearly pasty (colloide) degeneration of the follicles (white cor- 

 puscles of Malpighi). This disease, commonly known in Germany 

 as Wachsmilz (waxy spleen), is considered by some pathologists as 

 an albuminous or fibrinous effusion, by others as a fatty or pasty 

 degeneration. In point of fact, the follicles of the spleen from their 

 centre to their circumference are converted into an apparently homo- 

 geneous, transparent, grayish or yellowish mass, presenting a consi- 

 derable resemblance to the grains of boiled sago. I have long known 

 that these grains were composed of microscopic corpuscles, slightly 

 irregular in form, but perfectly homogeneous, which might be consi- 

 dered as resulting from the transformation of the lymphatic cells, 

 which constitute the contents of the follicles of the spleen. When 

 the effects of chemical reagents upon these corpuscles are observed 

 under the microscope, it is seen that they are rendered pale by acetic 

 acid, and that a granular precipitate is produced in the interstices of 

 the corpuscles when a little ferrocyanate of potash is added to the 

 acidulated preparation. Hot nitric acid produces a yellow colour, 

 which becomes brownish on the addition of caustic ammonia, owing 



* Ann. Nat. Hist, vol, xii. p. 481. 



