'304 Miscellaneous. 



if it be cut away, the animal, when once at rest, remains immoveable 

 upon the sand, without any indication of voluntary determination. 

 But it is still extremely sensitive, and regularly executes the move- 

 ments of the muscles of the belly which aid in respiration. I have 

 seen the general reflex movements persist for more than a week in a 

 decapitated Amphioxiis. 



The immersion of an Amphioxus in sea-water charged with blue 

 litmus (Vulpian's method) furnished no evidence of an acid secretion 

 in its intestinal tube, unless perhaps in the buccal cavity. As to the 

 large greenish appendage which is usually denominated the liver, I 

 have been unable to perceive, under the microscope, the production 

 of violascent spots by the action of acidulated tincture of iodine ; hot 

 nitric acid gives it a rather bright bottle-green colour. 



Neither in the liver and excrements, nor in those singular bodies, 

 diifering in different animals in number, size, and position, which J. 

 Midler regards as the kidneys, could I detect the presence of uric 

 acid by the microscopic reaction of murexide. 



I believe I am the first to have witnessed the ejection of the semen ; 

 it issues by the abdominal pore in a continuous jet, reinforced by 

 pulsations due to the abdominal muscles ; the spermatozoids, which 

 are free and active, retain their movements for about twenty-four 

 hours in sea-water (at 59° F.). They then measured : — head (J'003 ; 

 tail 0-040-0-048 milhm., but generally 0045 miUim. The detection 

 of this spontaneous emission of the semen is important, as it compels 

 us to regard the Amphioxus as an adult and definitive form. 



If the extremity of the body of an Amphioxus be cut off, the wound 

 does not cicatrize ; on the contrary, the tissues become gradually 

 disintegrated. I have seen animals, with only the tail mutilated, 

 become gradually eaten away up to the middle of the branchial region, 

 and live thus without intestines, without abdominal walls, and with- 

 out branchiae for several days. In this destruction the disks of the 

 dorsal cord become detached, and the muscular fibres become dis- 

 sociated, lose their striae, and disappear : the wound acquires a rosy 

 colour. 



Immersion for two minutes in water at 1 06° F. kills the Amphioxi ; 

 but although incapable of spontaneous movements, they are still lo- 

 cally contractile. Fresh water kills them with convulsions in two or 

 three minutes ; they then become opaque and rigid, and their muscles 

 no longer contract, even under the influence of induced currents in- 

 supportable by the dry fingers. If, then, the animal be again placed 

 in sea-water, contractility is seen to return in a few hours, and then 

 sensibility. If the cessation of the movement of the vibratile cilia 

 has been waited for, it reappears in sea-water, but contractility and 

 sensibility are finall}' lost. 



The presence in water of a very small quantity of strychnine kills 

 the Amphioxi with tetanic convulsions ; morphine stupefies them 

 (even when the cephalic extremity has been removed), leaving them, 

 however, when in small quantity, their sensibility ; lastly, curari 

 renders them immobile without affecting their conti-actility, and this 

 even when their integuments are uninjured. — Comptes Rendus, 

 August 26. 1867, pp. 364-367. 



