710 SCIENTIFIC RECORD FOR 1883. 



The homologies of the Kemertean proboscis. — Several uuexpected types 

 of the animal kingdom have been brought forward, from time to time, 

 as exemplifying in some form or other the notochord of the primitive 

 vertebrates. One of the most unexpected to furnish such a structure 

 is the Nemertcan, and yet Dr. Hnbrecht has claimed that the Neniertean 

 worms actually have the homologue of the notochord developed in a pro- 

 boscis. In his opinion "the proboscis of the Nemerteans, which arises 

 not as an imaginable structure (entirely derived, both phylogenetically 

 aud ontogenetically, from the epiblast) and which passes through a part 

 of the cerebral ganglion, is homologous with the rudimentary organ, 

 which is found in the whole series of vertebrates without exception — the 

 l^popbysis cerebri. The proboscidean sheath is comparable in situation 

 (aud development?) with the chorda dorsaiis of vertebrates." The chief 

 reason urged for this homology is that the proboscis and hypophysis 

 are both ectodermal invaginations. There are, on the other hand, rea- 

 sons which seem to strongly militate against this view. (Quart. Jour. 

 Micr. Sci., vol. xxiii, p. 349; Science, vol. II, p. G31.) 



Annelids. 



The /'unction of the Morrenian glands of the Earthworm. — The character 

 aud physiology of the glands observed by and named after the French 

 naturalist Morren have been investigated by C. Robinet. The secre- 

 tion of those glands, on drying, proves to be a mineral body, formed of 

 carbonate of calcium, whose tuuctions appear to be to adapt the ingesta 

 for nutrition ; this is supposed to be effected by four stages: 



(1.) The acids of the humus aie neutralized and converted into a 

 nutrient medium, a condition which is indispensable for the digestion 

 of the quaternary substances of the humus by the digestive fluid of the 

 hepatic glands. 



(2.) Part of the carbonates are transformed into soluble bicarbonate. 



(3.) The soluble bicarbonate acts on the humus, aud forms soluble 

 salts from the insoluble acids of the humus. The ulm ate of calcium, 

 which is formed by the action of the ulinie acid on the carbonate of cal- 

 cium, becomes soluble in the presence of an excess of carbonic acid. 



(4.) The soluble ulmate thus obtained is more easily absorbed in the 

 intestine. — (Comptes Rendus Acad. 8c. Paris, vol. xovn, pp. 192-194; 

 J. E. M. 8. (2), vol. in, p. 657.) 



VI r. ARTHROPODS. 



Merostomes. 



Sexual characteristics of the Horseshoe-crab. — The sexes of the Horse- 

 shoe-crab, when adult, are readily distinguishable by modifications of 

 the "claws" of the second pair of thoracic appendages, the female hav- 

 ing the penultimate joint prolonged in the axis of its body so as to be 

 parallel with and apposable to the last joint, while the male has the pe- 

 nultimate joint truncated at its distal extremity and the last joint ab- 



