389 



Equipment 



The equipment used in making the field observations was extremely 

 simple, and for the most part was as follows : 



1. A flat-bottom skiff of light draught, with wide stern. 



2. A black calico-covered sun-hood, so constructed that it could 

 be easily set up, clamped, and disconnected from the stern of the skiff. 



3. A small, hand water-glass, for close observation of tlie bot- 

 tom. This glass, cemented into the end of a 40-inch tube, 6X6 inches 

 in section, could be lowered to or very near bottom in as much as three 

 feet of water. 



4. A garden rake for lifting bog rush, smartweed, sodden, drift, 

 etc., on which eggs were seen, by use of the sun-hood or water-glass, 

 to have been deposited. 



5. The ordinary field collecting utensils employed in collecting and 

 preserving zoological material. 



We had also as field helper, at the oars and in every service in 

 which help was needed, an experienced, intelligent, and interested fish- 

 erman and mechanic*, to whom is due no small part of the credit for 

 whatever success attended the season's operations. 



Journal of Fikld Observations, 1910-1911 

 nineteen hundred and ten 



March. Although the month of March was exceptionally dry and 

 warm throughout, no reports of spawning of carp came in from fish- 

 ermen. The Illinois River gage stood at 14. i ft. March 15, and fell 

 gradually to 12.9 ft. by the end of the month. Between March 18 and 

 April I the surface temperature of the water in the channel of the 

 river, at our regular plankton station, rose from 44° to 60° Fahr., and 

 in Thompson's Lake, at the regular plankton station, it rose from 40° 

 to 60°. The plankton (silk-net catches) in Thompson's Lake was 

 nearly quadrupled in the week between March 18 and 25, and by 

 April I had increased to nearly nineteen times the amount present on 

 March 18. 



April. During the first half of April moderate weather prevailed, 

 water temperatures in the river and Thompson's Lake remaining be- 

 tween 60° and 64° Fahr. The river gage declined gradually through 

 the month, from 12.8 ft. to 10.2 ft. Between April 8 and 20, large 

 numbers of carp were reported to have been heard and seen "splash- 



*Henry C. Allen, of Havana. 



