30 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



''I tberefore made a series of suffocative experiments on im])regiiated 

 and nuimpreguated eggs, using aerated distilled water in cells, all of 

 tlie capacity of .05 cubic inch, [sealing the covers with hot wax, and 

 varying the number of eggs in .each cell. 



"Five observations were made with unin^pregnatad eggi}, having, 

 respectively, 35, 30, 18, 9, and 7 eggs in a cell; and although, in conse- 

 quence of the accidental loosening of the wax, and the entrance of a 

 little bubble of air, the duration of the contractions was not in all cases 

 inversely as the number of ova in the cells, yet the general result was 

 that both the rhythmic contraction and the pseudo cleavage continued 

 longer in the cells containing the smaller number of ova, the eggs 

 which lay nearest to the air-bubble always being the last to cease to 

 move; the accidental failure of the luting affording thus additional 

 evidence of the importance of oxygen. In all the cells the contraction 

 ceased in from 23 to 30 hours, or one-fourth of the time they continued 

 in aerated water and unlimited space. Five similar observations 

 were made on impregnated eggs, with 48, 38, 17, 10, and 7 eggs in 

 each cell, with similar but more marked results; the yelk-contrac- 

 tions ceasing earlier than in the uuimpregnated ova. The cleavage was 

 more rapidly checked than the pseudo cleavage, and still more so than 

 the yelk-contractions. 



"Seven experiments were then made to ascertain the relative depend- 

 ence upon the presence of oxygen of the movements which result in cell 

 multiplication and ditrcrentiatiou, and of the muscular contractions of 

 the embryo compared with the yelk-contractions. 



"Two healthy developing ova were sealed in similar cells at 76, 101, 

 127, 150, and 174 hours each, after impregnation, and two free embryos 

 at 24 an<l 48 hours after hatching. Although the proportion of active 

 organic matter to the medium was so very much less than in the pre- 

 vious experiments with recently-impregnated eggs, yet the process of 

 development ceased in all in about 7 hours, and the yelk-contractions 

 did not continue more than 18 hours. The movements of the heart 

 continued about the same time, those of the trunk ceasing before the 

 heart. The embryos in the later stages of development more quickly 

 ceased to move than those in the earlier. ^ 



"The inference is, I think, not to be resisted, that oxygen in the sur- 

 rounding medium is an essential condition of the exercise of the prop- 

 erty of rhythmic contractility possessed by the food-yelk, as well as of 

 the fissile contractility of the formative yelk." 



Though Dr. Ransom admits that the quantity of oxygen consumed in 

 these movements appears to be very minute, yet it indicates that a 

 large quantity of eggs coufiued in a small, air-tight space, would con- 

 sume the oxygen to an injurious extent, during a long journey, aud 

 sufficient ventilation is to be considered as one of the necessities in 

 iiacking eggs for transportation. 



The sawdust that filled the space around the inner can, in the Call- 



