472 EYCLESHYMER. [VoL. XIV.. 
two eggs the exovates were large. In two they were of the 
desired size. At the end of seventy to eighty hours the 
embryos appeared. In one egg the exovates occupied the posi- 
tions shown in Fig. 64. In the other they were on the opposite 
side of the median line, and just outside of the neural fold. 
At g a.m., April 2, five eggs were selected; of these, three 
were in the stage of crescentic blastopore, and two in stages a 
trifle later. These eggs were punctured in a region midway 
between the blastopore and the upper pole, as shown in Figs. 
65, 67, 69, 71. In from twenty-five to twenty-six hours, four 
had developed normal embryos, The other died during gas- 
trulation. 
In two eggs the exovates were later found in the middle of 
the embryo and far to the left of the median line, as shown in 
Figs. 66 and 68. In one egg (Fig. 70) the exovate was in the 
middle of the embryo, but far to the right of the median line. 
In the other (Fig. 72) the exovate was in the median line, and 
at about the same level as in the preceding case. 
At 8 a.m., April 3, an egg was selected, in which the early 
blastopore extended over an unusual distance; the egg was. 
punctured just above the centre of the blastopore, as shown in 
Fig. 73. At 12 m. the blastopore had changed to the form 
shown in Fig. 74, and the exovate had progressed toward the: 
lip of the blastopore. At 5 p.m. the circular form of the blasto- 
pore had been attained (Fig. 75). The exovate had now reached 
the verge of the blastopore; at 11.30 P.M. it was just at the 
anterior end of the linear blastopore. At 6 A.M. on the follow- 
ing morning, the neural fold had appeared, and the position of 
the exovate, with reference to this fold, is shown in Fig. 76. 
At 8 a.m., April 3, an egg in the stage of early blastopore 
(Fig. 77) was punctured a short distance above the blasto-. 
pore and directly over its middle point. At 5 p.m. the- 
blastopore had reached the semicircular form shown in Fig. 78. 
The exovate had approached the blastoporic margin; its. 
progress being much slower than in the preceding case. On 
the following morning the blastopore had reached the cir- 
cular form shown in Fig. 79. The exovate had continued its. 
progress toward the blastoporic margin. At 7 P.M. the neural. 
