154 Prof. Mcintosh's Notes from the 



The second tuft lia? bristles with simple wings. The rest 

 of the tufts in the anterior region have, in addition to the 

 simple winged bristles, two or more with sickle-shaped 

 or falciform tips, and in the ordinary preparations (micro- 

 scopic) these are posterior. These tips are translucent and 

 flattened, widened at the end of the shaft, characteristically 

 curved and tapei-ed to a fine poiut. 



The bristles of the posterior region are few in number 

 in the groups, and follow a blank space behind the anterior 

 region. Though smaller, the structure is the same as the 

 simple winged forms. The wings on the sleuder bristles of 

 the last three or four segments are very narrow — just 

 visible in living examples. 



So far as can be ascertained, the hooks in the various 

 forms correspond in iutimate structure. 



Though the Polychaeta as a rule are unisexual, various 

 hermaphrodite annelids are known; thus H. Parlin Johnson 

 gives a list of sixteen or seventeen species possessing" this 

 character. No form, however, is more interesting than 

 Filograna (Salraacinse) which not only is hermaphrodite, but 

 reproduces also by budding, as first pointed out by Huxley. 

 In the hermaphrodite annelids, as Malaquin clearly observes, 

 tlie male and female gonads may be quite distinct, as in the 

 Nereid Lycastis quadraticeps^ Gay, or they may be mixed, 

 as in Ophryotrocha puerilis. In the Salmacinae and Spiror- 

 bids, on the other hand, the male and female gonads are in 

 different segments. 



The budding in Filograna^ as Sars noticed, takes place in 

 the posterior region of the adult, viz., where the long paired 

 bristles occur — six or seven of these being in front of the bud, 

 which is formed of the caudal region of the nurse-stock with 

 the vent and its two papillae. 



The early buds are ovoid and granular, wider than the 

 ordinary caudal region, with nine or ten pairs of bristle-tufts 

 characteristic of the posterior region, the anterior division 

 being devoid of them, but having simple smooth filaments 

 representing the branchiae. No special difi'erentiation of the 

 granular interior of the bud can be made out, further than a 

 more opaque granular wedge in front of the anal papillae, 

 and which probably represents the adult rectum. No trace 

 of the collar is at first visible, then a fold, probably the 

 ventral, occurs at the base of the short filaments. 



In the next stage the body of the bud is more elongated, 

 the bristled segments are more numerous, and a streak along 

 tlie middle line leads to the vent, and is in contact anteriorly 

 with the alimentary canal of the adult, which in one con- 

 tained a large foreign mass about its middle. The branchiae 



I 



