January 1, 1880.] 



SCIENCE. 



17 



of experimentation have been much improved, 

 mainly by keeping up the spark of life, artifi- 

 cially, for a much longer time than was ever before 

 accomplished. 



A dog was prepared in such a way that a trans- 

 fusion of blood from its carotid artery to one of 

 the carotids of the head of the decapitated crim- 

 inal could be promptly made, and thus a supply 

 of living blood be made to flow through the life- 

 less head, and thereby preserve the excitability 

 of the nervous apparatus. Into the other carotid 

 (the right) of the head defibrinated blood at a 

 suitable temperature could be injected. The 

 head was received seven minutes after decapita- 

 tion. The difficulty of finding the carotids in 

 the soft tissues, which had become sadly disfig- 

 ured by the decapitation, caused a loss of ten 

 minutes. A small opening in the cranium was 

 then made, so as to insert a pair of electrodes on 

 the frontal parietal region of the left side, — the 

 presumable motor centre for the facial muscles. 

 At about twenty minutes after decapitation 

 the double transfusion of blood was begun. The 

 result was striking : a bright color returned to the 

 face, which also assumed a natural expression. 

 The effect was most marked on the left side, 

 which received its blood-supply direct from the 

 dog. The electrodes were inserted, but no result 

 followed. Thinking this might be due to a stim- 

 ulation of the wrong spot, they made another 

 opening in the skull, and again stimulated the 

 brain. This was followed by a regular and marked 

 contraction of the muscles of the opposite side of 

 the face, involving the orbicular and the super- 

 ciliary muscles, together with a movement of the 

 lower jaw, causing a strong chattering of the 

 teeth. This effect could be repeated at will up 

 to the 40th minute after decapitation, and, by 

 increasing the current used in stimulation, to the 

 49th minute. After this no movement followed 

 the application of the electrodes, although the 

 facial muscles could be made to contract by 

 direct stimulation of the muscles. The failure 

 of the first stimulation was afterwards shown to 

 be due to the unusual length of the head, thus 

 causing an error of a few mnlimetres in the 

 localization. At first the pupil could be made 

 to dilate and contract by the approach or with- 

 drawal of a strong light, — a fact frequently ob- 

 served in previous cases. The peculiarities of the 

 case are the great length of time for which the 

 excitability remained, and the means employed 

 for preserving this excitability, namely, the trans- 

 fusion of living blood. 



An opportunity of verifying these results pre- 

 sented itself in a subsequent case, but the results 

 of cortical stimulation were negative. The ex- 



planation was offered, that the individual had 

 furiously resisted the attempts of the officers to 

 put Ins body in position for decapitation, and that 

 the resultant neuro-muscular excitability prevented 

 the orderly action of the electrical stimulation. 

 However, a few new results were obtained. In 

 the first place, the patellar or knee reflex, obtained 

 by striking the tendon, was distinctly observed on 

 the body. The contraction was perfectly normal. 

 Another remarkable result was this : the cephalic 

 end of the medulla was stimulated in hopes of 

 exciting the nucleus of the hypoglossal nerve. 

 The attempt was successful, and movements of 

 the tongue such as follow direct stimulation of the 

 nerve were distinctly observed. 



Physiologists have not been very sanguine of 

 results from this method of research ; but it seems 

 that its importance has been rather underestimated. 

 It will never be available for original investiga- 

 tions ; but it will serve as a means of verifying 

 results otherwise obtained, and makes the infer- 

 ence from the facts with regard to animals to 

 similar conditions in man more reliable. 



PARASITISM AMONG MARINE ANIMALS. 



It is a curious fact that nearly all well-defended 

 marine animals are either brilliantly colored or 

 otherwise- attractive, as in the case of the sea- 

 anemone, jelly -fish, and tropical shells and crabs. 

 Those with little or no defence are generally 

 inconspicuous, or resemble surrounding objects. 

 This may be explained by supposing that by 

 being inconspicuous they easily escape the notice 

 of their enemies. Brilliant, well-defended animals 

 have little fear of enemies, and by their bright 

 colors attract curious animals within reach of 

 their deadly powers. 



Many a fish in the sea instinctively avoids the 

 deadly power hidden behind the brilliantly phos- 

 phorescent jelly-fishes. This protective light has 

 saved the jelly-fish much trouble, and is a great 

 aid to it in its struggle for existence among the 

 multitudes of surface animals. Through some 

 curious freak in evolution, an entirely inoffensive 

 cluster of animals, devoid of any protective power, 

 has gained the use of this phosphorescent light, 

 and, by imitating the dangerous jelly-fishes in this 

 respect, sails about the surface, inspiring terror 

 among surface animals that could easily devour 

 them. This cluster of animals is Pyrosoma. In 

 the clusters of floating seaweed in the Gulf 

 Stream there are vast numbers of tiny fishes 

 attired in the color of the floating weed, and that 

 certainly gain protection thereby. 



The lump-fish has a sucker on its body by 

 which it can attach itself to some fish of a similar 



