156 Prof. M'liitosli's N^oies from the 



pygidiam. The achetous region (of four or more pale seg- 

 ments) was filled with sperms — some ripe, the majority 

 scarcely ripe. The sides of the posterior region, which 

 ■would by-and-by form the bud, had opaque cells and 

 granules (developing ova?). The sperms thus first attained 

 maturity in the example. This, tlierefore, shows the variable 

 nature of the form in this respect. 



On the 9th June early trochospheres of a deep red colour 

 occurred in the vessels, the prototroch being conspicuous at 

 each side. These simply rotate or swim in small circles ; 

 but the larvae with commencing segmentation dart through 

 the water with great vigour, and often in a straight line, 

 M'hilst others made larger circles near the bottom. One of 

 the latter had three segments behind the head, and in all 

 two eyes were distinct. 



The mode of development in these forms thus differs from 

 that observed in the preparations of Salmacina oedificatric, 

 which produces large ova and trochospheres in the tube. 

 No buds have been met with. 



(J) General. 



Filograna in itself demonstrates the difficulties which 

 surround the idea of special creation as an explanation of 

 the diverse conditions of structure and reproduction, since 

 those witli and those without opercula, those with enlarged 

 tips to the branchiae and those without them, those with 

 eyes and those devoid of them, those with a few pairs of 

 anterior bristles and hook-rows and those with an increased 

 sei'ies of both, and other variations occur on the same site. 

 It is more reasonable to believe that the observer is dealing 

 with a species spread over the whole globe, and which is 

 endowed with a capacity for variation almost unequalled in 

 tiie animal series, than to adhere to the view that there are 

 separate species or genera. 



The sea is in a different position from Mr. Alfred Wallace's 

 view of the land, where " so long as a country remains 

 })hysically unchanged, the uuml)ers of its animal po])ulation 

 cannot materially increase, If one species does so, some 

 others requiring the same kind of food must diminish in 

 proportion.^' In the sea such strictures, perhaps, are less 

 necessary, for there is an ample margin for every living 

 form in so far as food is concerned. It is true " the numbers 

 that die" (or are killed) '' annually must be immense; and, 

 as the industrial existence of each animal depends on itself, 

 those that die must be the weakest — the very young, the 

 a^ed, and the diseased ; while those that prolong their 

 existence can only be the most perfect in health and vigoux* — 



