ASCARIS LUMBRICOIDES. 419 



eggs of Ascaris lumbricoides require at least a period of 11 — 12 

 months for the purpose. Even Richter's first statement spoke 

 of such a period ; according to a communication from him in 

 January, 1857, embryos had then began to be formed in eggs 

 which had been put into water by him in February, 1856, but 

 they did not move. Eggs which I placed in water in July, 1856, 

 do not yet show any trace of embryos. 



But as to what becomes of the ready-formed embryos we know 

 really nothing. Perhaps they get into our bodies with drinking- 

 water, and perhaps this is sufficient for their development, 

 although the administrations of the brood reared by Richter, by 

 myself to dogs, by Haubner to pigs, and also by Leuckart, led to 

 no successful result. Perhaps, however, this is not sufficient, 

 and a further migration through other animal bodies must 

 precede, although this mode is not very probable. 



2. Direct therapeutics. — From the immense number of remedies 

 recommended as Vermifuga, we should have rather tedious work 

 if they were all to be referred to here by name. If we wish to 

 treat the anthelminthic remedies in accordance with the claims 

 which physiological medicine makes upon us, we may adopt one 

 of two wavs, namelv, we must either seek out remedies which 

 quickly kill and poison the worms, without attacking the organism 

 of the host itself too severelv, or, as we usuallv see those worms 

 which apparently pass off spontaneously, come forth in a living 

 state, we must endeavour to discover by practice what remedies 

 there are especially, in consequence of which the worms begin 

 particularly to experience the desire of wandering outwards. 



1. Experiments for the discovery of remedies which poison 

 and kill the worms quickly have already been made to a greater 

 or less extent by Redi, Baglio, An dry, Leclerc, Torti, Coulet, 

 Arnemann, and Chabert. I willingly admit that Bremser thinks 

 it is not advisable to make use of human worms, which have 

 passed off spontaneously, or which have been found on dissection 

 some time after death for these experiments; but this, as well as 

 his further objection, that all round worms quickly die when 

 removed from their natural place of abode, and especially in the 

 open air, may be very easily answered. All that is necessary, 

 namelv, is to take intestinal worms from freshlv-killed health v 

 domestic animals, dogs or cats, and to put them into white of 

 egg, mixed with the medicament to be tested, at a temperature 

 equal to the normal heat of the intestine, or only a few degrees 



