Flights. — But little additional data of such a nature at 

 least as to change what has been recorded under this head 

 has accumulated during the intervening period. Mr. W. G. 

 Davis, of the Meterorological Bureau, Cordoba, has sub- 

 mitted the following remarks : 



"A few general considerations in connection with the 

 flight of locusts which I think we may assume as facts: — 1st, 

 that in the southern Hight in si3ring, the locust travels much 

 faster than it does on the return Hight in the autumn, or lat- 

 ter part of summer. ::^nd. In the spring it generally flies 

 during the warm hours of the day, when it takes advantage 

 of the greater velocity of the wind : whereas, on its return 

 to the North, it rises about sunset, travelling in the hours 

 when there is little if any wind. ord. The direction of the 

 flight in regard to the direction of the wind varies according 

 to the velocity of the wind. 



"Now, keeping these facts in view (provided they are 

 such) let us look at the salient features of the wind condi- 

 tion, taking our Cordoba results a characteristic of those pre- 

 vailing over the larger part of the Pamj)a region, and these 

 will practically hold good for the region to the north and 

 northwest from whence the locusts start in the Spring. 



' 'We note that the maximum movements for both the north 

 and south winds takes place in the months of August and 

 September, so that at the season when the locust is leaving 

 its hibernating grounds, it would be just as easy for him 

 to make his way north as south, /. e., the wind would help 

 him as much on one course as on the other : thus, it would 

 seem that it is purely instinct that leads the locust back to 

 the region where it was produced, also that it shapes the 

 course like a sailor both in flying before it and tacking and 

 is in a hurry to reach his destination, making shorter stops 

 on the journey and travelling in the hours when the wind 

 will most assist its flight. I may be entirely wrong in the 

 above supposition — I do not assert them as facts — but merely 

 l^resent them for your consideration." 



Natural Enemies. — Birds, Insects and other Ani- 



