170 Letters, Extracts, and Notes. 



Especially were Swallows there in immense numbers, 

 skimming by day over the river-bottom plain, especially over 

 parts of it where water was still standing, and gathering in 

 huge flocks to roost at night in the tall grass of the higher 

 ground. As mosquitoes were very abundant, it seems a 

 reasonable guess to suppose that the Swallows were attracted 

 by the numbers of mosquitoes upon which to feed. Only 

 two specimens of Hirundo rustica had previously been 

 obtained during many years collecting at various places in 

 this forest region. It would seem that the bulk of the 

 southward winter migration stops in Africa at the edge of 

 the great forest. 



Since I have naturally found little that was new lately 

 among the birds here at Bitye^ where 1 have collected so 

 long^ I have been turning my attention to a more thorough 

 study of the same old species. I wish I could say I had 

 been learning more about their habits and way of life^ which 

 would have been the most interesting kind of study; but my 

 eyesight is not good enough for that. I have been studying 

 pterylography, especially under wing-coverts^ which, as I 

 think, promise to furnish valuable taxonomic characters. 

 I have also been dipping a little into anatomy, and it seems 

 to me that I have already been rewarded by happening upon 

 a valuable discovery. 1 have found that the syrinx in birds 

 of the genus Smithornis is either entirely without muscles 

 attached to the bronchial serai-rings, or possesses possibly 

 a single pair of very thin muscles that have escaped my 

 notice. And having bethought me to dissect the muscles 

 and tendons of the leg and foot in the last specimen of 

 Smithornis obtained, I found that from the lower part of the 

 tendon of the Musculus flexor hallucis a slender vinculum 

 goes to the tendon of the M. flexor digitorum profundus, 

 uniting with it a little above the point where it divides into 

 branches going to the three front toes. I feel sufficiently 

 sure of the correctness of these observations to report them 

 now. But of course I will lose no opportunity of confirming 

 them, and I hope to make mjself more familiar with those 



