348 



SCIENCE. 



[N. S. Vol. XVI. No. 400. 



impervious cuticle, its spiracles and its sys- 

 tem of internal air tubes, would seem, of all 

 animals, the least likely to be able to take to 

 aquatic life. Yet the adaptation has been 

 successfully carried out on many different 

 lines. 



This paper set forth the diverse types of 

 devices that have enabled insects to rein- 

 vade the water— the primitive home of ani- 

 mal life — and to become in shallow fresh 

 waters a chief part of its fauna. Aquatic 

 insects fall naturally into the following eco- 

 logical groups : 



A. Forms breathing air directly. 



a. Living on the surface; water striders, 



spring tails, etc. 



b. Resting beneath the surface; foraging down 



below, carrying down a reserve supply 

 of air, diving beetles, back swimmers. 



c. Remaining down below, but in communica- 



tion with the surface; Ranatra, rat- tail 

 larvae, etc. 



B. Forms breathing the air dissolved in the 



water ( strictly aquatic ) . 

 a. Free swimming — Gorethra larvae, etc. 

 6. Ambulatory. 



1. Climbing and clinging forms. 



2. Sprav/ling forms. 



3. Burrowing forms. 



Of the strictly aquatic insects there are : 



1. Gill-less forms (living in well aerated water: 



size small ) . 



2. Forms with lamellate tracheal gills. May fly 



and damsel fly nymphs. 



3. Forms with filamentous tracheal gills, stone fly 



nymphs, etc. 



4. Forms with blood gills, and ha>moglobin in the 



blood. 

 a. Forms with tube gills. SimuUum pupte. 



(Discusssed by Messrs. Osborn and Sur- 

 face.) 



Tlie Habits of Fresli-ivater Lampreys 



(with lantern slides) : Harvey Adam 



Surface, Pennsylvania State College. 



The speaker presented numerotis lantern 



slides illustrating his paper 'Removal of 



Lampreys from Interior Waters of New 



York, ' published in the fourth Annual Re- 



port, Commissioner Fisheries, Game and 

 Forests of New York. (Discussed by Dr. 

 0. P. Hay.) 



The Significance of the Recent American 

 Cases of Hookworm Disease (uncinariasis 

 or anchylostomiasis) in Man: Ch. War- 

 dell Stiles, U. S. Dept. of Agriculture. 

 (Will appear in full in the Annual Re- 

 port, Bureau of Animal Industry for 

 1902.) 



The speaker maintained that hookworm 

 disease in man in this country is due to two 

 different organisms ; one of these, known as 

 Vncinaria duodenalis, has been imported 

 from Europe and Africa, and is now being 

 imported by the troops who are returning 

 from the Philippines; the other organism, 

 however, is distinctly American, and is 

 known as Vncinaria americana. This 

 parasite has thiis far been found in Virgin- 

 ia, Texas, Cuba and Porto Rico, and the 

 indications are that it is more or less wide- 

 spread in the southern states. The evi- 

 dence at his disposal leads to the well- 

 grounded suspicion that a number of cases 

 of anemia in the southern states, which 

 have heretofore been attributed to malaria 

 and which have not responded to the regular 

 treatment for malaria, are in reality cases 

 of hookworm disease. He further exhibit- 

 ed specimens of allied parasites which cause 

 similar diseases in other animals, such as 

 dogs, cats, sheep, cattle, wolves, seals, the 

 blue fox, etc. The so-called typhoid fever 

 of cats, for instance, has been traced to one 

 of these parasites, and is totally distinct 

 from typhoid fever in man. One of these 

 parasites also produces a very serious and 

 often fatal disease among dogs, another h 

 responsible for the death of many sheep in 

 the southern states, and still another is 

 responsible for the death of many yoiing 

 seals. The paper in question formed an 

 illustration of the important relation which 

 zoolog}^ bears to modern medicine. (Dis- 



