646 THE ANIMAL PARASITES OF MAN 



as shown by a distinct precipitin reaction. Galli-Valerio 1 considers 

 it likely that toxic substances are secreted by the living helminthes 

 which produce a lowering or raising of the body temperature, nervous 

 disturbances and haemolysis. Tallqvist 2 succeeded in extracting 

 from B. latns a lipoid-like body which had a strong haemolytic action. 

 The experimental anaemia thereby produced differed in no respect 

 from the severe chronic bothriocephalus anaemia of man. The 

 question as to under what special conditions severe, and sometimes 

 fatal bothriocephalus anaemia is developed is answered by Leichten- 

 stern 3 and by Lenhartz, 4 by the assumption that among the Bothrio- 

 cephali some are toxic, that is, manufacture a poison which, when 

 absorbed by the host, produces a severe anaemia. 



Certain factors lead him to conclude that an accumulation of 

 poison, dependent on time and place, occurs in the Bolhriocephali. 



In the case of ancylostome anaemia, experience so far, according 

 to Leichtenstern, 5 by no means supports the hypothesis of a difference 

 in virulence of the worms according to time and locality, ancylostome 

 anaemia being rather, so far as is known at present, in all races of 

 man, everywhere and at all times, simply and solely dependent on 

 the number of ancylostomes, the duration of the disease and 

 within certain narrow limits on the individual capability of resisting 

 the loss of blood and the toxic effect of the parasites. As is shown 

 by a short historical resume of the toxic action that has to be con- 

 sidered in ancylostome anaemia, we must admit that doubtless here, 

 as in the case of bothriocephalus anaemia, the toxins secreted by the 

 parasites exercise a haemolytic action, even while admitting Leichten- 

 stern's contention that the significance of the loss of. blood due to 

 ancylostomes must not be underrated. The toxic hypothesis acquired 

 a definite standing through a series of experiments of Lussana 6 on 

 rabbits, where he succeded in producing anaemia by injecting urinary 

 extracts of ancylostome patients. Arslan 7 extracted toxins from the 

 urine of two ancylostome patients and injected them into rabbits, 

 which thereupon sickened and showed the same blood changes as 

 the ancylostome patients. Retinal haemorrhages, so frequent in 

 ancylostome anaemia, which, according to Fischer 8 and Samelsohn, 9 

 are not due to direct loss of blood, must also be ascribed to a para- 

 sitic toxin. A further argument in favour of the toxic hypothesis 



1 Galli-Valerio, Therap. Monatsk., 1905. 



2 Tallqvist, Zeitschr. f, klin. Med., 1907, Ixi. 



3 Leichtenstern, " Handb. d. Therap. v. Pentzoldr.-Stintzing," 1898, 2nd edition, iv. 



4 Lenhartz, ibid., 1903, 3rd edition, iv, p. 607. 



"' Leichtenstern, Deutsch. med. Wochenschr., 1899. 



6 Lussana, Rivista Clin. Arch. ital. di din. Med., 1890. 



7 Aislan, Rev. mens. des Mai. de VEnfance, 1892. 



8 Fischer, Versamml. d. ophthal. Gesellsch., 1892. 



9 Samelsohn, ibid. 



