294 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



or may be made to involve all the muscles presented in the 

 cerebral hemispheres, with foaming at the mouth, biting of 

 the tongue, and loss of consciousness. When induced arti- 

 ficially in animals, the affection, as a rule, first invades the 

 muscles most in voluntary use, in striking harmony with the 

 clinical observations of Dr. Hughlings-Jackson. 



5. Chorea is of the same nature as epilepsy, dependent on 

 momentary and successive discharging lesions of the individ- 

 ual cerebral centres. In this respect Dr. Hughlings-Jackson's 

 views are again experimentally confirmed. 



6. The corpora striata have crossed action, and are centres 

 for the muscles of the opposite side of the body. Powerful 

 irritation of one causes rigid pleurosthotonos, the flexors pre- 

 dominating over the extensors. 



7. The optic thalamus, fornix, hippocampus major, and con- 

 volutions grouped around it, have no motor signification, and 

 are probably connected with sensation. 



8. The optic lobes, or corpora quadrigemina, besides 'being 

 concerned with vision and the movements of the iris, are 

 centres for the exterior muscles of the head, trunk, and legs. 

 Irritation of these centres causes rigid opisthotonos and tris- 

 mus. 



9. The cerebellum is the co-ordinating centre for the mus- 

 cles of the eyeball. Each separate lobule (in rabbits) is a 

 distinct centre for special alterations of the optic axes. 



10. On the integrity of these centres depends the mainte- 

 nance of the equilibrium of the body. 



11. Nystagmus, or oscillation of the eyeballs, is an epilep- 

 tiform affection of the cerebellar oculo-motorial centres. 



12. These results explain many hitherto obscure symptoms 

 of cerebral disease, and enable us to localize with greater cer- 

 tainty many forms of cerebral lesion. 20 A, Aug. 30, 1873, 233. 



MALFORMATION OF FISH EMBRYOS. 



Fish-culturists, especially those who have to deal with the 

 various species of the Salmonidce, are frequently struck with 

 the numerous cases of malformation in the embryos hatched 

 out by them ; these sometimes constituting a marked per- 

 centage of the whole number, resulting, it is supposed, from 

 too great rapidity of development, or some other at present 

 unknown agency. In some instances the percentage is so 



