90 



LUCERNARI^ AND THEIR ALLIES. 



teen-twentieths of the whole chondrophys. The mnermost of the three subdivisions 

 of the chondrophys, so conspicuous in the full grown individual, is not to be seen 

 us yet, although it is quite strongly marked in the next, and not much older phase 

 (Jigs. 82, 83, c*). 



181. The Nematocysts constitute a marked and very conspicuous feature in the 

 surface of the body, especially in the aboral face ; forming numerous, thickly scat- 

 tered, wart-like processes, by developing in closely set groups {fi(js. 30, 31, 32, Z). 

 On this account the outer wall appears much thicker than is really the case; 

 although its true depth is considerably greater than on the tentacles. In the full 

 grown animal these cnidigerous warts are so widely scattered that they scarcely 

 attract attention. In Cahadosia campanulata they arc, on the other hand, a singu- 

 larly prominent part of tlie physiognomy. 



182. The Eye-spots {fig. 32, 6).— In the paragraph (1[ 127, § 17) on the nervous 

 system of the full grown animal we have enlarged considerably upon the relation 

 of the so-called eye-spots to the visual function, and have spoken of them there as 

 interstitial deposits of pigment matter. The present stage of development is the 

 earliest one in which we have observed sucli accumulations. Here they form low 

 bosses, extending over about one-quarter the breadth of the oral face of the base 

 of the right anchors. The true nature of these bosses Avill be better illustrated in 

 the next phase (§ 23), showing that there are certain concomitant features in the 

 cellular mass of the wall in which they are situated. 



§ 23. Young, \ of an Inch. Across. (PI. iY,fig. 48; PI. \,fig. 53; 

 PI. \m,figs. 81-84; PI. ix, figs. 106, 107.) 



183. By the time the umbella has reached the diameter mentioned at the head 

 of this section the proportions of the body as a wliole are very similar to those of 

 a full grown individual, but are rather more slender. The transparency of the 

 body renders it more light and airy in appearance than its elder companions, and 

 in consequence seemingly less bulky and clumsy. The tentacles, however, still foil 

 short of the proportions of the highest development ; the shaft of the oldest mem- 

 bers of a bunch being, as yet, relatively quite thick. Tlie anchors (figs. 81, 82, 

 83), as has already been stated in a previous paragraph {*\ 169), have " lost a large 

 part of the shaft of the tentacular form, and the globose tip stands out like a liigh 

 knob on the oblique face of the colletocystigerous pad." Further details may be 

 learned by reference to the paragraphs 169, 170, 171. 



184. The Muscular System. — The opsoriiyoplaxic division of this system is clearly 

 defined throughout the umbella {figs. 53, 83, m, m\ in!'), and the tentacles {fig. 

 48, TO-), and anchors {figs. 82, 83, m'), but the oomyoplax {figs. 53, 83, m, m\ m'% 

 {% 74) is not visible. The former is distinctinctly fibrous, and of about equal 

 tliickncss in tlie different members mentioned, although apparently less in tlie pro- 

 boscis {fig. 53, ?«''), on account of its more regular outline on its proximal face. 

 In the latter organ, at this age, its abrupt termination at the mouth (p^) is very 

 distinctly seen without the help of the dissecting knife. 



185. The chonthom yoplax is more or less strongly marked by transverse stria- 



