380 JV. C. M'INTOSH [may 



the authors found no young stages, at least none shorter than 

 57 segments. They noticed the gradual growth of the eyes, the con- 

 dition of the mucous glands, and the ova. The spatulate bristles agree 

 with those of the first form (A) in having no process (crochet) at the 

 base of the terminal excavation. 



In the third form (B) they had 13 specimens, ranging from 19 to 

 51 bristled segments. No eyes were present in that with 19 bristled 

 segments, and only a pair of palps and branchiae. In the middle of the 

 body the spatulate bristles were pectinated, whereas posteriorly they 

 had the characteristic tooth below the excavation. They found large 

 eyes in one with 45 segments, and the transformation of the bristles 

 was complete at 46 segments (setigerous). The first 36 pairs of dorsal 

 fascicles showed only capillary pelagic bristles. Those with 51 

 setigerous segments had the palps reduced to buds. The presence of 

 gregarines in the perivisceral space was diagnostic. It is clear that the 

 bristles of this third form arise by gradual transformation from bristles 

 resembling those of the first (A). B gradually undergoes, therefore, a 

 physiological and a morphological transformation, the well-formed eyes, 

 pelagic bristles, and the atrophy of the palps being associated with the 

 development of the reproductive products. The authors, indeed, divide 

 the process into two stages, a first or preparatory period, and a second 

 or period of transformation. Besides the changes already noted in the 

 second stage, the branchiae show signs of reduction and are friable. The 

 animal ceases to take food, and its digestive canal atrophies (walls 

 become thin), the reserve eosinophile granulations are used up in the 

 development of the reproductive elements in the body-cavity, and seg- 

 mental organs are developed in all the abdominal segments. 



In reviewing their observations on the three forms and drawing 

 conclusions, Caullery and Mesnil consider that the three forms pertain 

 to the same polymorphic species, yet no males have been seen either 

 in the first or second form. Moreover, the latter (C) has been found 

 only in the adult and larger condition, and may be the final condition 

 of the former (A). 



The authors review the groups of the Cirratulidae, which they 

 divide into those with and those without large palps. They then 

 descant on the genus Hctcrocirrus, particularly on H. viridis, Langerhans, 

 a species having capillary bristles and long hooks, and which assumes 

 an epitokous condition — distinguished by the long swimming bristles, 

 the atrophy of the digestive tube, and the enlarged eyes. A similar 

 condition is met with in Heterocirrus caput-esocis, St. Joseph. They 

 also allude to the fixed epitokous condition of Tlioryx marioni, recog- 

 nised by the absence of eyes and the long capillary bristles. Choeto- 

 zonc, again, is a genus which, throughout all its stages, has the facies of 

 an epitokous form. They also institute a comparison between Cteno- 

 drilus and Dodecaceria, showing that their external form and internal 

 structure have considerable resemblances. The authors, in fact, consider 



