Iiivertebrata. Zoological Collections. 117 



be the envelope of the shell, and two cylinders with suckers, being a part of 

 the arms which surround the mouth of the animals of this family: unfortunately, 

 the mouth was destroyed. The two cylindrical tentacula were broken, but what 

 remained of them was in good preservation ; they were provided with 

 extremely delicate soft suckers, yielding under the least pressure, and indicating 

 little utility as organs of prehension. The tentacula upon which they 

 were placed were hollow, and contained a nerve and another cord, which, no 

 doubt, was the central vessel. The tentacula must have been long, if they 

 terminate like those of most cephalopoda. At a distance from each other 

 of from an inch to an inch and a half, they were connected by reticulated 

 muscular fibres. . .,, 



The posterior portion of this fragment was curved in the form of a tail. 

 All the lower part was of a bluish white, and composed of reticulated paren- 

 chyma, exceedingly soft and delicate in many points, but more firm in others. 

 The upper part was covered with reddish markings, formed of closely 

 approximated spots of the same colour. These irregular markings were 

 owing to the many ruptures which the skin had undergone ; in the entire 

 state, the animal would be uniformly red above, as was observable in some 

 parts. The tentacula and suckers were also of a reddish colour. 



The parenchyma of this molluscum is the same as that of the Pterotrachece 

 and CarinaricE. It swells itself out easily with sea water, and, on emitting 

 it, becomes reduced to a fifth or sixth of its natural size. 



If this animal be really a Nautilus, its inferior degree of consistency and 

 delicacy, and the small portion which is lodged in the shell, would explain 

 the difficulty of finding it entire, and the necessity of its inhabiting the 

 depths of the sea, where the water is always tranquil ; for the least agitation 

 of the waves, and the contact of the smallest body, would immediately 

 involve its destruction. 



The specimen is deposited in the Jardin du Roi. — Ann. des Sci. Nat. 

 August, 1830. jyai 'i^hnid •ii9il:t 9?u him ^A-ym aiiJ no mm x^a^ ."^aitnmin 

 JRem(Viks an a supposed spontaneous motion of the Bto6d.\ rBj^^^^^ 

 . ,, .;,;,f.,,. M.D. &c. (In a letter to the EditorJ^-ri^ot >I/f,^T.>r- 



Dear Sir, — At the meeting of naturalists in Heidelberg, in 1829, (see 

 report of their proceedings in Oken's Isis for May, June, and July, 1830,) 

 Professor Lichtenstein gave an account of some observations made in his 

 presence by Dr Czermack of Vienna, from which it was inferred, that the 

 globules of the blood, in several of the inferior tribes of animals, possessed 

 a power of spontaneous motion, independent of their connection with the 

 living textures. Although the report of these observations is very brief, 

 and, consequently, leaves some degree of uncertainty in regard to several 

 circumstances connected with them, yet I would venture to make them the 

 subject of a few remarks, as there are some facts of which the observers 

 seem not to have been aware, a due consideration of which should, I think, 

 lead us to question the justness of their conclusions. 



That the blood is endowed with a power of spontaneous motion, is an 

 opinion entertained by several eminent physiologists of Germany,* by some 

 on hypothetical grounds, by others as the result of direct observation. Among 

 the latter is the elder Treviranus : f he describes two motions observed in 

 blood recently drawn from the vessels ; one is a circular or whirling motion, 

 which either takes place at particular points in the drop of blood, or affects 

 the whole globules of which the drop consists. It lasts only a few seconds 

 after the blood is drawn, and is visible only with a lens of high magnifying 

 power. When the blood coagulates, the second motion commences : this, 

 which was previously described by Heidmann, \ consists in sudden contrac- 



* Kielmeyer, Treviranus, Kreyssig, Carus, Doellinger, &c. 



t Biologic, Baud iv. p. 654. % Gilbert's Annalen der Physik, b. 17j p. 1. 



