December 28, 1906.] 



SCIENCE. 



861 



carnivora and herbivora suggest that the habit 

 of living upon a diet consisting exclusively of 

 raw meat entails differences in the types of 

 bacteria that characterize the contents of the 

 large intestine. The occurrence of consider- 

 able numbers of spore-bearing organisms in 

 the carnivora points to the presence of an- 

 aerobic putrefactive forms in great numbers. 

 The results of subcutaneous inoculations into 

 guinea-pigs bear out this view and indicate 

 that the numbers of organisms capable of pro- 

 ducing a hemorrhagic oedema with tissue 

 necrosis, with or without gas-production, are 

 very considerable. Unfortunately, the data 

 pertaining to the biological properties of these 

 pathogenic anaerobes are at present insuffi- 

 cient to permit us to classify them or to say 

 more of their nature than that they are organ- 

 isms representative of a definite group of 

 putrefactive anaerobes which make butyric 

 acid and hydrogen and exert a peptonizing 

 action upon living tissues. Nevertheless, the 

 observations here recorded are of much in- 

 terest in relation to the bacterial processes 

 and nutrition of herbivorous^ as distinguished 

 from carnivorous animals and are significant 

 furthermore for the interpretation of bac- 

 terial conditions found in man. The question 

 arises whether the abundant use of meat over 

 a long period of time may not favor the de- 

 velopment of much larger numbers of spore- 

 bearing putrefactive anaerobes in the intes- 

 tinal tract than would be the case were a dif- 

 ferent type of proteid substituted for meat. 



Inquiries made of Dr. Blair, the pathologist 

 at the New York Zoological Park, elicited the 

 fact that while, upon the whole, the carnivo- 

 rous animals are apt to live somewhat longer 

 than the herbivorous animals of about equal 

 size, the carnivora are much more likely to 

 develop conditions of advanced anaemia in the 

 later years of their lives than is the case with 

 the herbivora. Dr. Blair states that it is usual 

 in the later years of life for the carnivora to 

 show a much diminished volume of blood and 

 at least a moderate fall in the hemoglobin. 

 Instances are stated to be not uncommon in 

 which a pernicious type of ansemia has devel- 



^ Many of the herbivora yielded mixed flora in- 

 capable of making gas on dextrose bouillon. 



oped in the carnivora. On the contrary, 

 among the herbivora it is said that pronounced 

 anaemias are very occasional. The examples 

 of severe anaemia encountered among the her- 

 bivora were said by Dr. Blair to be in nearly 

 all instances referable to gross animal para- 

 sites. 



The information now available indicates 

 that man occupies a position between the her- 

 bivora and carnivora with respect to the num- 

 bers of putrefactive anaerobes that are present 

 in the digestive tract and their proportion to 

 the total number of bacteria. The influence 

 of a purely vegetable diet on the one hand 

 and of a strict meat diet on the other, upon 

 these anaerobes, is much in need of careful 

 investigation. C. A. Hebter. 



THE EXCEPTIONAL NATURE AND GENESIS OF THE 

 MISSISSIPPI DELTA. 



At the December meeting of the Cordilleran 

 Section of the American Geological Society, 

 1905, I read a paper under the above title, an 

 abstract of which, printed on the program, is 

 copied below: 



This paper discusses the wholly exceptional ma- 

 terials and form of the lower delta of the Missis- 

 sippi river, as observed by the writer in 1867 and 

 1869, and described and discussed in the American 

 Journal of Science in 1871. Following out the 

 suggestions of Lyell, and the disputed statement 

 of Humphreys and Abbott that the alluvial de- 

 posits of the great river are only of slight depth, 

 the writer investigated the extreme mouths of the 

 Passes, the ' Neck ' and the similar minor, bird- 

 foot-like arms projecting beyond. It became ap- 

 parent that the silty river deposit on these nar- 

 row dikes or banks is only superficial, and that 

 their resistance to erosion during overflows is due 

 to their being mainly composed of tough, inerod- 

 able ' mudlump clay.' Tliat these mudlumps, ob- 

 served and described by Lyell, are upheavals of 

 the river bottom, and are formed of such clay as 

 is deposited outside of the bar, where the turbid 

 water of the river meets, and is clarifled by, the 

 saline sea water. Also, that the mudlump up- 

 heavals occur in tlie main outlets or passes of the 

 river, as a direct result of their being the main 

 outlets. No mudlumps then existed in the South 

 Pass, but now that it has been artificially made 

 the main channel, mudlump upheaval has taken, 

 and is taking, place. Mudlump formation is thus 



