OF THE ROTATORIA. 473 



Gosse, viz. with Arthropoda and Insects. He supports this notion by an 

 appeal to the structure of the maxillary apparatus and to supposed analogies 

 of its several parts with the mandibles, jaws, &c., of insects. The " mastax " 

 (see chapter on Digestive Apparatus) he identifies with a true mouth ; the 

 <' mallei " with mandibles ; the " manubria " possibly with the cheeks, into 

 which the " mallei " are articulated ; the "■ rami " of the " incus " with 

 maxillae ; and the "fidcrum " he imagines to represent the '^ cardines " sol- 

 dered together. "VMiile maintaining this connexion with Insecta through 

 the maxillary organs in their highest development, he suggests their affinity 

 with Polyzoa by the same organs at the opposite extremity of the scale, since 

 the oval muscular bulbs in Bowerhmikia approach and recede in their action 

 on food, and seem to represent the quadrigiobular masses of Limnias and 

 Botifer further degenerated. If this affinity be correctly indicated, the in- 

 teresting fact is apparent that the Polyzoa present the point where the two 

 great parallel divisions Mollusca and Articulata unite in their course towards 

 the tme Polypi (see Mr. Gosse's valuable paper in the Phihsoplikal Trans- 

 actions, 1855). In a memoir since read before the Koyal Society (Phil. 

 Trans. 1857) by this same distinguished natiu-alist, the Crustacean alliance 

 is further insisted on upon the ground of the sexual pecuharities of the Ko- 

 tatoria. In this paper the author remarks that we must look, for a parallel 

 to the curious facts established concerning the dioecious character of Eotifera 

 and theii' peculiar males (see p. 455), to the Crustacea. " The economy of 

 the Hectocof}jlus of certain Cephalopod Mollusca, though perhaps even still 

 more abnormal, is only remotely analogous. Xor is the parallelism very close 

 of those Entozoa in which the males are organically united to the females, as 

 the genera Heteroura and Si/ngamus, described by Professor Owen. 



" In the class Crustacea, however, many examples occur of a sexual differ- 

 ence, which may instructively be compared ^vith the one before us. Thus, 

 among the Isopoda, we find the parasitic genera Bo^yrus, Pliryxus, and lone, 

 in which the males are notably smaller than the females, very diverse in 

 fonn, and in some respects inferior in structure. In the Siphonostoma ' the 

 males are extremely smaU, and do not in the least resemble the females,' 

 though those of different genera bear a strong resemblance inter se, even 

 when the females are very dissimilar. So low is their grade of organization, 

 that Burmeister has attempted to prove these minute creatures to be embry- 

 onic or larval forms. And, finally, in the Cirripedia, Mr. Darwin has proved 

 the existence of males in the genera IbJa and ScaJjjeUum, which are very 

 minute as compared with their females, excessively abnormal in form, and in 

 some respects in an embryonic condition, though unquestionably mature, as 

 shown by the spermatozoa. And, what is still more interesting, the same 

 accurate zoologist observes — ' After the most careful dissection of very many 

 specimens, .... I can venture positively to assert that there is no vestige of a 

 mouth or masticatory organs, or stomach.' Again, he describes the internal 

 structure as ' a pulpy mass with numerous oil-globules,' and the sperm- 

 vesicle as ' a pear-shaped bag at the very bottom of the sack-formed animal, 

 containing either pulpy matter, or a great mass of spermatozoa,' — terms which 

 might have been employed in describing some of the male Brachioni. 



'• In all these analogies I conceive we may find additional reasons, to those 

 that have been before adduced, for assigning to the Eotifera a zoological po- 

 sition among the Articulata." 



The attempt of Mr. Gosse to identify parts of the maxillary mechanism of 

 Rotatoria with that of Insects, although praiseworthy, is in our opinion un- 

 successful, and involves a considerable stretch of imagination. Moreover, if 

 the identifications, or more correctly speaking the homologies, be correct, we 



