512 



SCIENCE 



[N. S. Vol. XXXIII. No. 



any difiference that the anemia would be less 

 among the hands of the first generation; (4) that 

 the greater proportion of severe eases of anemia 

 will be found in such rooms as the card room 

 where there is the greater amount of lint flying 

 around, less severe cases in the spinning room, and 

 no severe eases in the cloth or engine room where 

 there is little or no lint; (5) that persons fresh 

 from the farms will not be very anemic but will 

 become more so the longer they work; (6) and 

 that if the anemia is due to the lint it is not very 

 extensive or severe in the knitting mills, the paper 

 mills, or the orphan asylums, or among medical 

 students or trained nurses, since the persons in- 

 volved here have little or no contact with lint, 

 investigation shows that in a general way the con- 

 trary is true in the above assumptions. 



(1) Not a single case of cotton-mill anemia was 

 found in the New England mills, although over 

 2,000 had been seen in the southern mills. (2) In 

 the Carolinas, Georgia and Alabama, there is a 

 relatively low percentage of eases of anemia in 

 the central clay lands, a greater number of cases 

 and more severe cases are found in places where 

 the hands come from the sand or mountain lands, 

 the worst cases coming from the sand lands. 

 (3) Even where they were located in new mills 

 with better sanitary provisions, the generation 

 fresh from the farms showed a greater percentage 

 of anemia than the hands who were one or two 

 generations removed from the farm. (4) In 

 general the cases of cotton-mill anemia are more 

 severe and frequent in the spinning room than in 

 the card room, and the most severe ease found in 

 one mill was in the cloth room. (5) Of 59 cases, 

 39 per cent, had been in the mills less than a year 

 and 61 per cent, had been there more than a year. 

 It seems that 94 per cent, of these eases might 

 theoretically be considered as hookworm infections 

 persisting after removal from soil pollution, and 

 in a number of eases of severe anemia the persons 

 had just entered the mill. (6) The most anemia 

 found in any establishment was in a knitting mill, 

 where 68.8 per cent, had typical "eotton-mill 

 anemia. ' ' This same anemia was found in paper 

 mills and colleges, and 18 cases were found in an 

 orphanage among children who had never worked 

 in the mills. 



The above findings lead to the conclusion that 

 the ' ' cotton mill anemia ' ' has nothing to do with 

 working in the cotton mills. It is due to hook- 

 worm disease, contracted in most eases on the 

 farms as a result of the insanitary conditions 

 existing in the rural districts, and brought to the 



mills from the farms. There is less anemia 

 among mill workers than among the farm tenants, 

 owing to the fact that life under the improved 

 sanitary conditions of the average cotton mill is 

 better from the public-health point of view than 

 life as a tenant on a soil-polluted farm of the sort 

 from which so many of these people come. 



Mr. Crawley presented a paper entitled ' ' Ex- 

 periments on the Transmission of Trypanosomes 

 by Glossina," in which he reviewed the work of 

 Bouet and Eoubaud. These workers instituted a 

 series of experiments with Trypanosoma dimor- 

 phon, T. ca^alboui and T. peoaudi, and the tsetse 

 flies, Glossina palpalis, G. tacMno'ides and G. 

 longipalpis. It was found that any one of the 

 three species of Glossina functioned eqvially well 

 as host for T. caealboiii. Observations with the 

 other trypanosomes have not been completed. 

 Plies bred in the laboratory, and hence free from 

 parasites, were permitted to feed on an infected 

 animal and later were fed each day on a series of 

 ' ' clean ' ' animals. It was found that the first 

 feed or ' ' infecting repast ' ' was followed by a 

 latent period of six days, during which the 

 trypanosomes in the fly are innocuous. The fly 

 then becomes infective and for some time at least 

 the number of trypanosomes within it undergoes 

 a progressive increase. The fly presumably re- 

 mains infective as long as it lives. 



An examination of the infected flies showed 

 that the infection was confined to the proboscis, 

 in the labrum, the flagellates are of the Lepto- 

 monas type and are fixed to the wall. These de- 

 velop into trypanosomes which occur in the in- 

 terior of the hypopharynx. They are either at- 

 tached to the walls by the ends of the flagella, or 

 free and motile in the interior of the organ. They 

 never ascend beyond the common canal of the 

 salivary glands, but always amass in considerable 

 numbers in the vicinity of the opening of this 

 canal into the hypopharynx. 



These trypanosome forms appear in the hypo- 

 pharynx forty-eight hours after the infecting feed, 

 and are abundant by the fourth day. The au- 

 thors regard these as the infecting elements, and 

 call attention to the fact that the incubation 

 period is not marked by morphological changes, 

 but rather by changes of a physiological nature 

 as regards the virulence of the parasites. 



In all, 20 per cent, of the flies fed on infected 

 animals became infected. 



Maurice C. Hall, 



Secretary 



