INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 925 



causal relation with the disease. The chief reasons adduced may be 

 summed up as follows : — 



1. It is by DO means proved that the various forms of Bacillus, 

 Spirillum, &c., occurring in certain diseases are specifically distinct 

 from forms having no relation whatever to any pathological 

 conditions. 



2. All the representatives of the Schizomycetes may be and 

 have been introduced into the blood without causing any morbid 

 symptoms.* 



3. In the diseases supposed to be due to bacteria, the microphytes 

 are "never to be detected in the earlier stages of the disease, but 

 only at a brief period before and after a fatal termination." 



4. " The poisonous properties of septinous blood and of other 

 decomposing animal solutions gradually disappear toward the third or 

 fourth day, a fact which is scarcely reconcilable with the doctrine 

 that the poison resides in the almost imperishable ' spores ' of the 

 bacilli, which existed during the earlier stages of decomposition." 



5. Septinous fluids retain their virulent properties after filtration 

 through fine porous materials, the effect of the filtration being to free 

 them from " visible molecules of every description." 



6. " The coagulum produced by boiling a septinous fluid is more 

 virulent than the fluid itself." Eleven hours' boiling does not destroy 

 the poisonous properties of such a fluid ; a watery extract of the 

 residue of such a fluid evaporated to dryness has an intense toxic 

 effect. 



7. The poison (septine or sepsin) of some of these fluids may be 

 made to combine with acids so as to form salts, which latter retain all 

 the toxic properties of the original fluid, t 



8. The living tissues, under the influence of a chemical irritant 

 (iodine or ammonia), may secrete a virulent fluid, capable of com- 

 municating disease from animal to animal. 



Mr. Lewis concludes " that the living tissue elements of the body 

 itself play a much more important part in the elaboration of 

 septinous and allied poisons, than what has of late been ordinarily 

 ascribed to them." 



Crenothrix polyspora, the Cause of the Unwholesomeness of the 

 Berlin "Water.:|: — According to Dr. Zopf, this is a nostoc-like fungus, 

 which has developed, from some unknown cause, in enormous quanti- 

 ties in the wells of Berlin. The filaments are enclosed in a gelatinous 

 envelope; but the cells readily become isolated, and develop into 

 new filaments. There are also very minute gonidia produced by 

 division of the cells of a filament ; these are also enclosed in gela- 

 tinous envelopes and develop into filaments, and, under certain 

 circumstances, into palmella-like colonies of cells. From the absence 

 of chlorophyll, Crenothrix appears to occuj)y an intermediate position 



* With regard to these two points, cf. Koch, ' Wundinfectionskraiikheiteii,' 

 ante, p. 754. 



t The possibility that the non-living contagium indicated in §§ 5, 6, and 7 

 may itself be a result of organic actiun, should not be lost sight of. 



X ' Entwickelungsgeschichtliche Untersuchung liber Crenothrix pohjspora,' von 

 Dr. W. Zopf, Berlin, 1879 ; see ' Bot. Zeit.,' xxxvii. (1879) p. 54G. 



