356 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1952 



and has almost displaced all other treatments previously used for 

 this purpose. Lead arsenate is rapidly displacing older treatments 

 for the removal of tapeworms from ruminants. The recent discoveries 

 of anthelmintic drugs also have opened up opportunities to parasit- 

 ologists for careers with commercial firms that manufacture or formu- 

 late anthelmintic and other parasinoidal chemicals. 



DISCUSSION 



It is evident from the discussion of even a few of the problems with 

 which the livestock parasitologist in the United States has been dealing 

 that the research findings and action programs based on them have 

 been directed mainly to the conservation and increase of food and 

 fiber, needed by a population that has been steadily increasing. How- 

 ever, it is evident also that the production of livestock cannot be 

 increased indefinitely, because our available grasslands and our capac- 

 ity to grow livestock feed are limited to a large extent by our geo- 

 graphic boundaries. Since extending our geographical frontiers is 

 certainly not part of our national policy or ambition, our increased 

 food production in the future will require, among other things, 

 pushing steadily to the new frontiers that are opened up by scientific 

 discovery. 



How soon we shall reach a saturation point in our ability to support 

 the increasing numbers of livestock that will be needed in keeping 

 with the growth of our population, and how extensive this increase 

 will have to be, cannot now be predicted. It should be borne in mind, 

 however, that great progress is already being made in developing ge- 

 netically superior strains of food-producing animals and in discovering 

 superior methods of preventing virus, bacterial, parasitic, nutritional, 

 and other diseases of animals, as well as suppressing their insect pests. 



Whether we shall be able to support indefinitely an increasing popu- 

 lation is a question that has already aroused considerable discussion. 

 The neo-Malthusians, who take the pessimistic view, foresee dire con- 

 sequences in increasing populations, especially in countries that are 

 already overcrowded. They regard the introduction of new and im- 

 proved public health measures into the so-called backward countries 

 as merely hastening there the approach of mass starvation. Also, 

 they charge that the introduction of life-prolonging measures merely 

 aggravates the food problem in those parts of the world that already 

 have teeming populations, now living on a low nutritional plane, if 

 not actually facing famine. In fact, they ask bluntly what is accom- 

 plished by saving millions of people from malaria and other diseases 

 in the world's most congested areas, if this will merely result in 

 giving them added time to suffer from malnutrition and finally die 

 of starvation. 



