MISCELLANY. 



253 



mediately after the last moult, a number of 

 these were shut up in paper boxes, five to 

 ten in a box, and deprived of food. If, two 

 or three days after confinement in the boxes, 

 any of the larvae were found wandering 

 about, they were fed very sparingly. Near- 

 ly all of them lived to complete their trans- 

 formations. Another lot were, in like man- 

 ner, put in boxes, but supplied with abun- 

 dant food. From the latter came sixty- 

 eight females and only four males ; from 

 the former seventy-six males and only three 

 females. Five larvae that were eating vig- 

 orously were also taken from their food a 

 day or two before they would have been 

 sated. Of these, four turned out females. 



Another experiment was this: Soon 

 after the last moult, twenty larvae were de- 

 prived of food for twenty-four hours. Then 

 ten of them were given abundant food again, 

 as long as they would eat. One of these 

 met its death by accident in the chrysalis 

 state, but all the rest became female but- 

 terflies. Of the other ten, two died in the 

 chrysalis state ; the remainder were males. 



Again: Some twenty half-grown larvae 

 of the Vanessa antiopa were accidentally 

 deprived of food. Twelve of them died of 

 starvation, but the remainder completed 

 their transformations. On dissection, these 

 eight all proved to be males. The indefati- 

 gable student pushed her investigations fur- 

 ther still, for, having found thirty-three lar- 

 vae of an unfamiliar species, she fed them 

 abundantly, till they would eat no more. 

 The rare and beautiful moth Dn/ocampa 

 rubicunda made its appearance in due time, 

 and there were twenty-nine females and 

 only two males, the remaining two having 

 either escaped or died. Finally, a lot of 

 the same species of caterpillars were left 

 without food. Some of them were killed 

 by a parasite, others died of starvation, and 

 the seven which survived were all males. 



Hydrophobia and the Imagination. The 



period of time which elapses between the 

 bite of a rabid animal and the appearance 

 of hydrophobic symptoms varies over a 

 very wide range indeed. The disorder sel- 

 dom makes its appearance earlier than the 

 eighth clay after inoculation (if inoculation 

 there be) ; or, again, the virus may be hid- 

 den in the wound for weeks, months, or 



even years. Physicians say that, in most 

 cases, hydrophobia manifests itself in from 

 four to eight weeks after the bite, though 

 there are many authentic cases where the 

 period of incubation extended over eight or 

 nine months, and in one instance even as 

 long as seven years. In this term incuba- 

 tion is implied an hypothesis gratuitously 

 assumed, and scarcely susceptible of direct 

 demonstration. It is found that a patient 

 bitten by a rabid animal passes a certain 

 length of time without manifesting hydro- 

 phobic symptoms, and it is supposed that 

 the germs of the disease have been slowly 

 maturing. But, as there is no other disease 

 whose period of incubation is so long or so 

 varying in duration, the hypothesis which 

 traces hydrophobia to animal virus finds 

 no foundation in analogy, and is conse- 

 quently very weak. 



It is, therefore, very natural that medi- 

 cal men should begin to study the whole 

 question anew, and attempt other explana- 

 tions of this disease. Thus, Dr. D. H. 

 Tuke, whose paper on the " Blanching of 

 the Hair" appeared in our December num- 

 ber, has lately published a work on the 

 " Influence of the Mind upon the Body," 

 and there supports the proposition that hy- 

 drophobia is produced solely by the action 

 of the imagination. The author cites cases 

 where, beyond all doubt, hydrophobic 

 symptoms were developed without inocula- 

 tion. A notable instance is that of a phy- 

 sician of Lyons, named Chomel, who, hav- 

 ing aided in the dissection of several vic- 

 tims of the disorder, imagined that he had 

 been inoculated with the virus. On at- 

 tempting to drink, he was seized with 

 spasm of the pharynx, and in this condi- 

 tion roamed about the streets for three 

 days. At length his friends succeeded in 

 convincing him of the groundlessness of his 

 apprehensions, and he at once recovered. 

 Rush also tells of cases of spontaneous hy- 

 drophobia, which arose from no other cause 

 but fear and association of ideas. 



A German physician, too, Dr. Marx, of 

 Gottingen, as we learn from the Clinic, is 

 disposed to take this view of hydrophobia, 

 and to regard it as a psychical affection, the 

 result of morbid excitement of the imagi- 

 nation. He is of the opinion that the bite 

 of a mad dog does not, of itself, produce 



