November. 1918] 



The Ottawa Naturalist 



91 



and June this year I kept a series of eggs of 

 Limnaea stagnalis, Planorbis corneus and Valvaia 

 piscinalis under observation for the early stages of 

 development. I have a large number of eggs em- 

 bedded for future cuttmg, after using pereny and 

 acetic sublimate as fixing reagents. Towards the end 

 of an egg-laying period in L. stagnalis, I frequently 

 found some of the egg-capsules with numerous eggs, 

 up to fifteen m number instead of the normal single 

 egg. I also managed to hatch cut several cases of 

 two embryos from one capsule. A curious incident 

 occurred with the aquarmm in which there were 

 specimens of P. corneus and the only specimen of 

 Paludina vivipara I have been able to find. One 

 night five of these snails including the Paludina, 



course on the Protozoa, while I continued a course 

 cf twenty lectures on Heredity. At Christmas, 1915, 

 the left of Barracks 6 became available for educa- 

 tional purposes, and the first weeks of the new year 

 saw the conversion of a corner of a somewhat 

 dilapidated hay-loft into a biological laboratory. By 

 the end of January the accommodation for eight 

 microscopes was provided. The necessary glass- 

 ware and reagents were got in from Messrs. Leitz, 

 and practical botany, of a necessarily elementary 

 character, was started with twenty-one students. 



In the following terms regular lecture courses in 

 botany were given by myself, and the corresponding 

 practical work was of a more thorough and exten- 

 sive nature. The ground covered has been as fo!- 



tlic camp is made up of students from the public scliools 

 and universities," Ruhleben, Germany. 



were dragged cut of the aquarium and devoured by 

 a rat. The aquarium is now removed to a safer 

 place for protection from further invasion." 



Report of Biological Activities in Ruhleben. 

 From Michael S. Pease, B.A., Cantab., dated 

 August 14, 1917. 



"The first outward sign of biological activity in 

 Ruhleben appeared in the spring of 1915, when Dr. 

 A. E. Lechmere started a series of lectures on 

 Elementary Biology. These were held in a disused 

 betting-booth, and attended by half-a-dozen enthu- 

 siasts. In the summer, one of the grand stands was set 

 aside for lectures, and Dr. Lechmere continued his 



lows: Bryophytes and Pteridcphy'es (Summer, 

 1916); Gymnosperms (Autumn, 1916); Algae 

 (Lent, 1917); Angiosperms (Summer, 1917). 



Spirit material was kindly presented to us by 

 Prof. A. C. Seward, Dr. Darbishire, and Prof. 

 Tubeuf. 



We are indebted to Prof. Engler for a weekly 

 supply of flowers from the Kgl. Botanischer Garten, 

 Dahlem, for the systematic course. A pond within 

 the race-course has been cur source of fresh ma- 

 terial for Algae and Protozoa. 



The equipment of the laboratory has been con- 

 tinuously improved. A cable was laid on to give 

 us electric current day and night. A transformer 



