280 



THE MICROSCOPE. 



form. About 1,600 polypes are situated on a square inch 

 of surface of the mass, consequently the number of polypes 

 in one specimen, which weighed 17 ounces, and measured 

 14 \ inches in circumference, * may be computed at 106,000, 

 and the tentacula at 5,320,000!'" This family is now 

 classed with the Polyzoa : see Professor Allman's beauti- 

 fully illustrated monograph of all the British species ; 

 published by the Ray Society, 1857. 



Trembley gave an excellent and interesting account of 

 the family of Alcyonella. Mr. J. Newton Tomkins has 

 kindly furnished the following observations, on the de- 

 velopment of a specimen of Alcyonella Stagnorum: 



" The ova, now under examination, (^-inch obj. A. eye- 

 piece 100 lin. diain., Wollaston's condenser,) are the 



products of some healthy 

 specimens of Alcyonella stag- 

 norum, given me by Mr. 

 Lloyd, and sketched in full 

 activity in September, 1856, 

 fig. 171. Soon after this 

 period their movements de- 

 creased in energy, numerous 

 ova were detached, which 

 floated to the surface of the 

 water of the jar in which 

 they were confined, and in 

 the course of a very few 

 weeks no trace remained of 

 the parent animals, except 

 a spongy mass of an almost 

 gelatinous character, which 

 still exists, though devoid of 



definite form > and a PP eai l 



COmpOSed of a maSS Of 

 i__._i_ ori QTir q Hi<anra-flni<tPr} 



broken and disorganised 



cells. 



" In November, with a view of preserving the water in 

 a normal condition, I introduced a sprig of Anacharis 

 Alsinastrum, and finding it grew freely, but soon covered 

 with a filamentous confervoid growth, threw in two small 

 water-snails, which are there still. About January last, 



tifer vulgaris, and Voriicella campa- 

 nulata, adherent to the same. (Mag- 



nified 100 diameters.) 



