SPIROCILETOSIS IN THE LOWER ANIMALS 717 



very much more marked (250 times more so) in the blood of rats which have 

 been hyper-immunized by the inoculation into the peritoneal cavity every 

 other day of O25-1 c.c. of blood rich in spirochsetes. The blood of animals 

 treated in this way has therapeutic properties as well (Novy and Knapp). 



If the serum of such hyper-immunized rats be inoculated either before or at the 

 same time as the virus it will in quantities of 0*002 c.c. protect a rat against an 

 inoculation of O'l c.c. of spirochsete-infected blood. If inoculated in quantities 

 of 2 c.c. into rats showing Spirochsetes in their blood it will cause all the parasites 

 to vanish once and for all within an hour. In those species subject to relapses (mice, 

 monkeys) the serum will prevent the initial attack but the subsequent relapses come 

 on as though the animals had not been treated with the serum. 



The immunity conferred by an inoculation of the serum would seem to last 

 more than 2 months in rats, mice and monkeys. 



The differentiation of the various human Spirochsetes. 



The different Spirochaetes parasitic in the blood of man can be differentiated 

 by means of the serum reactions. The serum of a rat hyper-immunized 

 against a given species of Spirochsete will agglutinate that species and will 

 cause it to undergo granular disintegration both in vitro and in vivo (cf. 

 Pfeiffer's phenomenon) : but has no action or at most a very slight action on 

 other species (Uhlenhuth and Handel). 



The method of crossed immunity does not afford such a sharp means of 

 differentiation. There is always an active crossed immunity between 

 S. recurrentis and S. novyi : crossed immunity is less often observed (in 

 about 50 per cent, of cases) between S. recurrentis and S. duttoni and very 

 seldom between S. duttoni and S. novyi (Uhlenhuth and Handel). Frankel 

 whose results are rather different has observed no crossed immunity between 

 S. rossii, the Spirochsete found by Koch in German East Africa and S. 

 duttoni of West African fever. 



B. SPIROCH^TOSIS IN THE LO WER ANIMALS. 

 1. Spirochceta anserina. 



8. anserina, an organism similar to 8. recurrentis was found by Sakharoff at 

 Tiflis in a disease of geese. 



Morphologically, 8. anserina is very like 8. recurrentis but is a little shorter, 

 thicker and less undulating. It cannot be grown on the ordinary laboratory media. 



In infected geese the Spirochsetes are present in the blood for several days then 

 they suddenly disappear and the birds die of toxaemia after surviving the infection. 

 Post mortem the internal organs will be found to have undergone fatty degeneration. 



The experimental disease has been carefully studied by Cantacuzene. Geese, 

 ducks, young chickens, sparrows, and pigeons are all highly susceptible : adult 

 fowls and rodents are immune. 



To demonstrate the Spirochsete in sections of the tissues Cantacuzene gives the 

 following technique : 



1. Cut the tissues into very small pieces and fix in Flemming's solution for 24 

 hours. Wash in water for 24 hours. 



2. Embed in paraffin (xylol method). 



3. Cut very thin sections, fix them on the slides and stain for 24 hours in the 

 following solution : 



Carbol-fuchsin, - - 2 parts. 



Neutral glycerin, 1 part. 



4. Wash rapidly in water, blot up the excess of water, dehydrate in several lots 

 of pure ether for 4-6 hours and mount in balsam dissolved in ether. 



In susceptible animals the Spirochsetes multiply in the blood after inoculation 

 and disappear from the circulation as soon as the temperature falls. The Spirochsetes 



