1^JU7.] NATURAL SCIENCES OF PHILADELPHIA. 323- 



which forms the capsules, are poured out of the ovuluet into a small 

 cavity in the folded foot. Here the capsule-forming material conies 

 into contact with the sea water and hardens, after which the capsule 

 is releasetl from the foot and another is formed. The average length 

 of time taken by Sycoti/piis in forming a capsule is about three hours, 

 and as the ''egg string" may contain as many as seventy capsules, 

 the egg laying may cover a period of several da^'s. 



The eggs of Fidgur are laid at Beaufort, N. C, during the months of 

 May and June principally.- Sycotypus lays its eggs at Woods Hole 

 late in August or early in September. The rate of development in 

 these gasteroi)ods is very slow. I can give no definite figures as to 

 the length of the period of development, since the eggs which have 

 been brought into the laboratory do not long continue to develop nor- 

 mally, but from such evidence as I have been able to gather I conclude 

 that the development within the capsules occupies several months; 

 indeed I have frequently found egg strings in midwinter with partially 

 developed embryos, indicating that the eggs which are laid in the fall 

 may not hatch until the following spring. As might be expected where 

 eggs are so greatly laden with yolk, the entire embryonic and larval 

 development is passed within the egg capsules and the young hatch 

 in practicall}' an adult condition. 



3. METHODS AND MATERIAL. 



The eggs of Fidgur and Sycotypus are very soft and are difficult to- 

 preserve. When removed from the \-ery thick jelly in which they are 

 enclosed within the capsules they usually flatten into thin disks under 

 their own weight, or become otherwise distorted. There are no eo"- 

 membranes except those formed by the surrounding gelatinous sub- 

 stance, and the thin pellicle of protoplasm which surrounds the egg is 

 too w^eak to preserve the spherical shape or even to retain the yolk 

 unless the eggs are floating in water or jelly. Since the jelly must 

 in most cases be removed before the fixation of the eggs, special means 

 must be employed to prevent them from bursting or becoming dis- 

 torted. ]\Iany rapid fixing fluids, such as hot sublimate, alcohol and 

 alcohol-acetic mixtures, cause the eggs to crack open, or even to split 

 into fragments after they have been apparently well fixed. After 

 experimenting with many fixing fluids, the only successful method 

 of preservation which I have found, is to open one side of the capsule 



- 1 wish here to acki^nvledgc my indebtedness to Hon. George ^I. Bowers 

 U. S. Commissioner of Fisheries, and to Dr. Caswell Grave, Director of the 

 Fisheries Station at Beaufort, for the many courtesies extended to me while L 

 was at the Beaufort Station. 



