No. i.] 



STUDIES UPOX II J 7)A'i >.!//;/> ( '.s'. / E. 



37 



to remove sufficient of the margin. If the least portion was 

 left, or even a portion quite near the margin, automaticity 

 was retained, but by removing carefully and completely some 

 2 or 3 mm. of the bell-margin I was able to confirm quite 

 fully the experiment of Romanes : on 

 Scyphomedusae. 



After various expedients had failed, 

 resort was had to bits of rather fine shoe- 

 maker's bristles, cut into proper lengths. 

 These were thrust through the gelatinous 

 portions of the Medusae in such directions 

 as would serve to fairly secure the desired 

 contact of the surfaces to be united. An 

 inspection of the several figures will give 

 the best idea of how this was secured. 

 Cf. Figs. 8 and 9. But at best the 

 method was only partially successful. It 

 may be mentioned in this connection 

 that one of the difficulties attending these 

 experiments was the danger of deleterious 

 contamination involved in the whole of 

 the operations from Bacteria and parasitic Infusoria invading 

 the water and impeding or destroying the experiments. This 

 was much more noticeable in experiments on Medusae than on 

 Hydroids, a fact due in part, certainly, to the promptness with 

 which the latter reacted in regeneration of tissues as compared 

 with the former. Notwithstanding, it is rather remarkable that 

 so small a proportion in either case suffered, since no special 

 pains were taken in the way of critically guarding against 

 contamination beyond the more ordinary provisions of clean 

 glassware and instruments. To maintain a fairly equable 

 temperature during unusually hot days, the covered vessels 

 containing the specimens were set under the running water 

 taps of the laboratory. 



1 Jellyfishes, etc., p. 27 ct seq. 



