CONDITION, OF UNCINAKIATED PUPS. 77 



ments made by Dr. Stiles and eliminating trampling as an important source of death 

 to any but very young pups. The first pup secured for dissection was obtained from 

 Lukanin rookery on July 24, although noted as dead on July 22. No part of this 

 rookery was crowded, and the dead seal lay on a sandy spot, strewn with bowlders, 

 not far from several harems. On dissection the pup proved to be fat and well 

 nourished, the stomach containing a quantity of milk. There were no bruises and no 

 signs of disease save a slight discoloration of the median part of the small intestine, 

 which might well have been caused by decomposition. The intestine was, however, 

 slightly nodular or swollen in spots throughout this discolored area, and on cutting 

 open these nodes the mucous membrane was found to be broken down and the swollen 

 part filled with mucus and blood. Moreover, in each swelling there were many 

 Uncinaria, the total number in the 3 feet of intestine affected being large, and the 

 wall of the intestine being marked by numerous cyst-like spots, where the parasites 

 had been attached. The flesh was pale, and but little blood, and this thin and watery, 

 present in the heart and large vessels, the indications being clear that death had 

 resulted from loss of blood and general anaimia produced by the attacks of Uncinaria. 



From this time onward, owing to the opening out of the rookeries, it became gradu- 

 ally more and more easy to obtain specimens for examination, and between July 25 

 and September 4 some 345 pups were dissected, revealing the existence of Uncinaria 

 in all favorable localities, and showing that this parasite was by far the most impor- 

 tant factor in the death rate among pups. After my departure on August 20, the work 

 of dissection was carried on actively by Messrs. E. E. Snodgrass and A. W. Greeley, 

 of Stanford University, who prosecuted the work up to September 4, the date of their 

 departure. 



From our combined observations it would seem that the disease is at its height 

 from July 15 or 20 to August 20, and that it ceases about the 1st of September. 



WhiljB we failed to recognize Uncinaria as the cause of death in 1896, yet after 

 August 22 of that year only two pups were found that had not certainly starved to 

 death. In the light of subsequent work it is evident that one of these \^as a case of 

 death resulting from inflammation caused by Uncinaria, and it is probable that the 

 other was from the same cause. Both were from the worst infected localities on 

 St. Paul, one being from Polovina, the other from Tolstoi. In 1897 Messrs. Snodgrass 

 and Greeley found two cases of death from Uncinaria after September 1, but the 

 summer of 1897 was warmer and drier than that of 1896, and as equally careful search 

 was made in both years for other sources of death than starvation it is possible that 

 for climatic reasons the ravages of the parasite were continued to a later date in 1897 

 than in the previous year. 



Since but two pups out of many scores are known to have died from Uncinaria in 

 1896 after August 22, and but 15 out of 106 actually dissected after August 20 are 

 known to have died from Uncinaria in 1897, it is assuming too much to say that any 

 considerable number of pups dying after September 1 have perished from that 

 cause.' 



'Professor Thompson, Report on His Mission to Bering Sea in 1897, p. 8, writes: "And, further- 

 more, the existence of this cause of death gives us the right, though in what measure we do not know, 

 to deduct to a very cousiderahle extent from the number of pups that die in the latter part of the 

 season when we seek to estimate the loss due to starvation as a result of pelagic slaughter of the 

 cows. It was shown last 'year that one-half the mortality of pups occurred before pelagic sealing 



