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of which seemed to cross the river or to go to cattle standing in the 
middle of the stream. The cattle on clear days came to the river 
about 9 o’clock in the morning, and remained standing in the middle of 
the river until 5 o’clock in the afternoon, when they went to grazing, to 
return at 9 o’clock the following morning. Most of the cattle stood on 
flat rocks protruding out of the water, so that no part of their body or 
legs were submerged; but in spite of this fact, while they were standing 
in the river they were unmolested. The actual oviposition of these 
insects, which are found to occur in such extraordinary numbers, was 
witnessed on March 1 and the two or three following days. An old and 
feeble animal, which had laid down and had not strength to rise, was 
observed to be attacked during this time by about 50 flies, of which 
upward of a dozen were captured. The flies were observed to approach 
Fig. 44.-HYPODERMA LINEATA: a, eggs attached to hair; b, c, d, dorsal, ventral, an d lateral view of 
egg; e, embryonic or first larva, as seen in egg; f, g, mouth-parts of same enlarged; h, anal segments 
of same still more enlarged (original). 
very swiftly and deposit their eggs anywhere on the sides, belly, or 
tail, near the anus, and on the front legs. The flies were left unmolested 
im Many cases until, after remaining on or about the animal from five 
to ten minutes, they flew off. The eggs were then found without dif- 
ficulty, usually placed four to six together, and fastened to the hair. 
Flies were also captured and eggs were deposited in confinement. A 
iarge number of the flies and eggs, both dried and in alcohol, were sent 
tome. The structure of the lower portion of the egg, which has been 
more or less correctly shown in some of the earlier illustrations, is well 
adapted for clasping’a hair. It consists of two lobes, forming a bulb- 
ous enlargement, which is attached to the egg by a broad but rather 
thin neck, so that when the latter is viewed sidewise it appears as a 
Slender pedicel. (See Fig. 44 a, d.) 
