Notices of New Books. 4687 



wound,and proceeded to dissect a somewhat globular mass of foetuses, 

 bounded by the intestines before, and separated from them by an 

 indescribably thin, diaphanous membrane ; this mass was further 

 bounded above by the spine and ribs, below and behind by the 

 posterior inferior abdominal walls, bulging backward of the anal 

 orifice and fin. The exterior envelope of this oblong globe consisted 

 of a very thin, pellucid, extremely delicate and apparently laminated 

 and flocculent membrane, like the amnion of the human embryo in 

 the early state : it did not form a simple sac, but consisted of many 

 duplications, like the arachnoidal reflections among the sinuosities 

 and convolutions of the human brain, sending its prolongation as the 

 hyaloid membrane does through the vitreous mass of the eye. This 

 uterine membrane (ovisac it cannot be termed) contained twenty-two 

 fishes. It is probable that the inner surface of the uterine membrane 

 sent forth a still more delicate membrane, which enveloped each fish 

 after the manner that the peritoneum envelopes the abdominal viscera; 

 but the parent fish, and still more its enclosed organs, were too minute 

 to admit of full demonstration during a necessarily hurried examina- 

 tion; moreover, the wish not to mutilate the parent fish very much 

 prevented a fuller dissection of the foetal mass in situ. Each foetal 

 fish was doubled laterally, sometimes to the right, sometimes to the 

 left, into a globular form : the caudal fin, which is inclined to the 

 lancet shape, though blunter, overlapped one eye and one side of the 

 mouth : each fish in situ, and even after forcible extraction from its 

 bed, was enfolded in a sac : some were drawn out united by pedicles 

 to a common stem, somewhat like an umbilical cord. These foetal 

 fishes presented a perfect example of close packing. A perceptible 

 force was required to dislodge them from their beds. The concavity 

 left by their extraction appeared to be lined with a smooth, black, 

 peritoneal membrane. The intestines, which were very minute, were 

 crowded forward by the rounded mass of foetuses which occupied the 

 greater portion of the abdominal cavity. No ova were discovered. 



"Without attempting fully to describe even the dermal skeleton, I 

 may observe that this tiny fish is a most symmetrical one. Its minute- 

 ness may be imagined when I state that after the removal of the 

 enclosed foetuses it weighed only seven grains, though not dis- 

 emboweled. Thorough desiccation would probably reduce its weight 

 one half or more. The fish exposed for two hours in the shade on a 

 damp day was but slightly desiccated. It was weighed by Mr. Mac- 

 pherson, apothecary, in my presence; but fearing a mistake I had it 

 weighed a second time, with the same result. If each fcetus weighed 



