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in the ears or the nasal fossae. From these eggs the larvae are- 

 hatched in a few hours. They burrow in the tissues, devour the 

 mucous membrane, muscles, cartilages, the periosteum, and even 

 the bones, thereby causing terrible sores, and not infrequently,, 

 particularly when they attack the ear or nasal fossae, death by 

 penetrating to the brain. The larval stage of another insect,. 

 Cordylohia antliropophaga^ burrows into the skin of man and 

 animals, and produces an inflamed swelling, from which it 

 emerges after six or seven days. The lecturer then gave an. 

 example of an insect parasitic only in the adult stage. This was 

 a flea, not unlike our common species, and almost universally 

 known as the " chigger." It greedily attacks all warm-blooded 

 animals, including birds and man. Until impregnated the 

 female, like the male, is free, feeding intermittently as oppor- 

 tunity offers. So soon as she becomes impregnated the female 

 avails herself of the first animal encountered to burrow diagonally 

 under the skin, where, being well nourished by the blood, she- 

 proceeds to ovulation. By the end of this process the abdomen,, 

 in consequence of the growth of the eggs it contains, has attained 

 the size of a small pea. During gestation the " chigger" causes 

 a considerable amount of irritation, and, owing to this, pus forms 

 round the distended abdomen. After the eggs are laid the super- 

 adjacent skin ulcerates, and the " chigger " is expelled, leaving a 

 small sore, which, if infected by any pathogenic micro-organism,, 

 such as the bacillus of tetanus, may lead to grave consequences. 

 As a cause of suffering, invaliding, and indirectly of death, it 

 'is an insect of no small importance. It was formerly restricted 

 to the West Indies and America, but is now extremely prevalent 

 in Africa, and on the east coast has caused a large amount 

 of invaliding amongst the Indian coolies there, by whom it 

 has been introduced into India. 



Dr. Simpson then passed on to the consideration of the second., 

 ^'roup namely, those insects which act as mechanical transmit- 

 ters of disease. This process is simplicity itself, and, unfor- 

 tunately, is not connected in any way with the life-history of 

 the insect, nor with any special anatomical peculiarity. They 

 simply act as vehicles of pathogenic organisms indiscriminately 

 accumulated. An insect, by settling on a sick person or animal,, 

 or on their excretions, may pick up disease germs, either on the 

 proboscis, wings, body or feet. Later on, the same insect alights- 



