2 BULLETIN OF THE 



disposal. I thought it would be desirable, nevertheless, to procure an 

 additional supply of eggs and embryos, and especially to endeavor to rear 

 the youug beyond the stages already in my possession. 



On account of my duties in College it was impossible for me to leave 

 Cambridge until nearly the middle of June, — almost a month after the 

 usual time of spawning. Nevertheless, owing to the extreme backward- 

 ness of the season, I hoped that I might be able to procure some mate- 

 rial, and was confirmed in this by correspondence with Mr. J. H. Perry, 

 through whom I learned that up to a day or two before the time I had 

 fixed upon for setting out the gar- pike had not spawned. 



I arrived at Black Lake on the evening of June 13th. The weather 

 had meantime grown warm, and the fish had already spawned, but I was 

 able to secure some eggs which were not very far advanced in develop- 

 ment. By a number of processes I killed and preserved at short inter- 

 vals sets of embryos which presumably belonged to the same lot of 

 spawn. The eggs which were collected from different localities were 

 kept in separate earthen-ware dishes and supplied with fresh water every 

 twelve hours. In this way the embryos were easily kept alive until they 

 hatched. Then they soon attached themselves by means of their pecu- 

 liar maxillary disks to the sides of the dishes, and near the surface of 

 the water, where they cluug with a tenacity truly surprising. 



A number of eggs were preserved — principally by means of Kleinen- 

 berg's picro-sulphuric mixture — at intervals of a few hours, beginning 

 on the afternoon of June 14th and extending through several succeeding 

 days. This method was controlled at intervals by preservations made in 

 alcohol, in chromic acid, in osmic acid followed by potassic bichromate, 

 and in the last named reagent alone. 



Besides the large number of embryos which were preserved at Black 

 Lake, I took away with me (June 20) many more — upwards of a hun- 

 dred — which had recently hatched. These living fishes were carried in 

 a narrow-necked tin pail, to the sides of which they adhered very firmly. 



Instead of returning directly to Cambridge I took the gar-pike with 

 me to my summer residence on the south shore of Lake Erie, about 

 forty miles southwest of Buffalo, N. Y. Although this journey extended 

 over more than three hundred miles the fishes survived it well. The 

 greater part of it, however, was rendered comparatively easy, since it 

 was made by steamboat instead of railway. It is fortunate for such an 

 undertaking that these fishes have so large a yolk-sac, since it obviates 

 the necessity of procuring food for many days after hatching. 



The question of being able to raise them beyond the stages already 



