same way Fuhrmann must not be blamed for the methodologically harmful 

 statements of Eichler, Szidat, and others. "The rule of Fuhrmann" is 

 independent although there are numerous statements to the effect that he 

 never "invented" anything himself, but only repeated the previously stated 

 vievvs of Braun, Leuckart, and Ehring. The first among them spoke 

 generally that the organisms which feed upon other organisms owe their 

 appearance to the organisms which feed them, that is, that the develop- 

 ment of the animal world (and also of predaceousness and of parasitism 

 subsequently) could not precede the appearance of free-living organisnns 

 feeding at the expense of unorganized media. A different interpretation 

 should be considered as being far-fetched and it is inadmissible to say, 

 as I. A. Rubtsov (1940) did, that: "If under the 'appearance' of 

 organisms one understands their development, then in the words which 

 were cited were expressed the thought about conjugate evolution of the 

 parasite and the host" (? !). The expression of Leuckart about the 

 frequency of occurrence of parasites among different hosts, ■which in his 

 opinion depends directly on their consanguinity with the basic host, is 

 related on the other hand to the problem of specificity (see page 245 ), The 

 naethod of Ehring can be reduced to the comparison of the fauna of different 

 geographical regions and the evaluation of the significance of the study of 

 interrupted ranges of parasites for the deter nnination of the tinne of the 

 occurrence of this break (in distribution, nobis), that is, it brings in a 

 completely different circle of questions. As a matter of fact, Fuhrmann 

 also exannines the problem of the geographical distribution of tapeworms 

 of the birds, referring directly to Ehring and criticizing himi rather 

 sharply (Fuhrmann, 1909, pages 21-23), 



However, "the rule of Fuhrmann" can be applied not only to 

 endoparasitic worms but, as is obvious from what has been said before, 

 it can be extended to monogenetic trematodes (see pages 300-320) and to 

 a number of other ectoparasite groups as well (Rubtsov, 1940; 

 Blagoveshensky, 1950, 1953; Dubinin 1953, and others). 



Thus, to replace "the rule of Fuhrmann" by the "seventh" 

 statement of ecological parasitology (according to V, A, Dogiel) in any of 

 his interpretations is impossible because the latter cannot be applied to a 

 number of larger groups of ectoparasitic animals the infection of which is 

 not affected by the means of alimentation of their hosts. Consequently the 

 opinion of G, S. Markov is not true in essence; V. A. Dogiel (1948) is not 

 completely right either when he speaks about the undermining of the 

 meaning of "the rule of Fuhrmann" by the data of ecological parasitology. 

 However, if in speaking about endoparasites we would be inclined to agree 

 with M. M, Dubinin about the role of the similar form of life and the 

 alimentation of food in the evaluation of causality "of the rule of Fuhrmann, " 

 this is far from being so clear for the ectoparasites. Actually we have p. 297 



already shown that in a number of cases in the infection by the same species 

 of parasite, the basic role is played by the physiological consanguinity which 



342 



