124 bulletin: museum of comparative zoology. 



time to time made the following notes on the condition of the spawn, 

 which was brought to Cambridge, where I arrived on the 26th of April : 



'Eggs hiid at about 12 o'clock (noon) April 22, 1903. About (jO% 

 to 70% proved to be fertilized. 



April 23. Infertile eggs grayish in color. Some of them may have 

 been injured in transportation. 



April 24, 4.15 P. M. Egg envelopes becoming attentuated, not 

 so stiffly gelatinous. Strings tending to float (due to decomposition 

 of infertile eggs?). 



April 25, 8.00 A. M. All embryos ha\e pierced their envelope and 

 are clinging to it by the head, on the outside (of the envelope). In- 

 fertile eggs still remain in their envelopes. 



9.30 A. M. First perceptible movements, slight quivering; embryos 

 still adhering by head to remains of envelope. 



April 26, 8.30 A. M. Much more active; those where envelope 

 entirely consumed moving about with motion of larvae of mosquito. 

 Some clinging to leaves. 



9.30 A. M. All freely swimming. 



April 27, 8.00 A. M. All swimming or clinging to sides of aquarium.' 



E. L. Mark." 



In addition to this, Plate 2, fig. 7, 6 show eggs and young tadpoles 

 which were collected by L. J. Cole in July of the same year (1903). 

 The eggs closely resemble those of B. americanus both in size and 

 appearance. Shrinkage of the eggs in the formalin in which they are 

 preserved makes it almost impossible to identify, the exact stages of 

 development, but it is plain that none of the eggs were past the early 

 cleavage stages. The tadpoles are black in color and resemble, those 

 of B. americanus. They measure from 8.5 to 10.9 mm. in length. 

 They have the typical early tadpole form. The buds of the hind limbs 

 are present, but hardly visible to the naked eye. 



This material was dated July 27 and July 31, 1903. The following 

 note shows where it came from: 



" B. B. S. Station 1406, Jul^r 26, 1903. 



A small fresh-water pond to the west of the Midflle Road just south 

 of ' Green Hill.' Pond only 20-30 feet from the roadside (Lat. 17' 58" 

 Long. 44' 52"). Pond is about 20 feet long and 8 feet wide. At 

 present contains about 1^ Ft. water from heavy rain early in the 

 morning (3 A. M.) of July 25th. The water of the Pond is green with 

 some microscopic alga. Bufo marinus breeding in large numbers. 



L. J. Cole." 



