Febbuaky 9, 1906.] 



SCIENCE. 



209 



the flagellates found in the intestinal canal 

 of insects and othex" sanguivora. The in- 

 testinal contents can be spread directly 

 over the plates in the manner indicated. 



The Action of So-called Complementoid in 

 Immune Serum: W. H. Manwaring, 

 Indiana University. 



Working with goat serum, immunized 

 against sheep corpuscles, the action of so- 

 called complementoid was estimated quan- 

 titatively and plotted graphically. From 

 the curves so obtained, the following con- 

 clusions are drawn: 



1. Hemolytic 'complementoid,' added in 

 increasing amounts to hemolytic serum, or 

 to an ai-tificial hemolytic amboceptor-com- 

 plement mixture, causes, at first, a rapid 

 increase in hemolytic power. 



2. This increase soon reaches an apparent 

 maximum, after which a further increase 

 in 'complementoid' causes: (I.) no change, 

 (II.) a rapid diminution in hemolytic 

 power, or (III.) a slow increase in that 

 power. 



3. This variability in the action of 'com- 

 plementoid' Avhen used in large amounts, 

 depends, at least in part, on the length of 

 time the serum is heated to produce the 

 ' complementoid. ' 



4. The action of 'complementoid' is so 

 pronounced that quantitative work that 

 does not take its presence into consideration 

 is practically valueless. This applies to 

 such experiments as those forming the basis 

 for the doctrine of 'deviation of comple- 

 ment. ' 



5. It would be difficult to explain the 

 action of 'complementoid' by means of any 

 of the existing hypotheses regarding the 

 action of immune serum. 



6. No conclusion is yet drawn as to 

 whether the so-called complementoid is 

 reaHy a degeneration product of comple- 

 ment, or whether it may not be a mixture 

 of spilt-products of other serum compo- 



nents, or, in part at least, certain thus-far 

 unrecognized thermo-stable components of 

 normal serum. 



Abnormal Cheese Troubles due to Lactose 

 Fermenting Yeasts: H. L. Russell and 

 E. G. Hastings, University of Wisconsin. 

 The defective trouble in cheese here de- 

 scribed is due to the presence of a milk 

 sugar splitting yeast. This type of micro- 

 organism grows rapidly in milk or whey, 

 especially when the same contains a con- 

 siderable amount of acid. The milk sugar 

 is decomposed and alcohol and carbonic 

 acid formed in abundance, as well as unde- 

 sirable flavored products. The organism 

 causing this trouble is destroyed at the 

 temperature of 60° C. in ten minutes, but 

 is capable of resisting the high tempera- 

 ture '(55° C.) for thirty-five minutes, which 

 is used in the manufacture of Swiss cheese. 

 This type of organism is introduced into 

 the milk primarily through the medium of 

 certain customs that commonly prevail in 

 Swiss cheese factories. First, the cold 

 process of recovering the butter fat. Whey 

 is held over from one day to the next in 

 order to permit the fat to rise, and this 

 gives an opportunity for the souring proc- 

 ess to go on, and consequently favorable 

 conditions for the development of these 

 yeasts. 



Second, soaking the natural rennets in 

 old sour whey and adding this rennet ex- 

 tract solution to the fresh milk. These 

 processes afford ideal conditions for the 

 growth of the yeast germ and consequently 

 permit of the infection of the fresh milk. 

 Studies of the distribution of this type 

 of organisms show them to be much more 

 abundant in regions where Swiss cheese is 

 made than where the American cheddar 

 system is practised. Yeasts have not here- 

 tofore been i-ecognized as important fac- 

 tors in dairy processes, except in a few 

 cases, but where conditions of manufacture 



