ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ^1 



and the intestine is constricted at regular intervals by these septa. 

 There are three pairs of longitudinal nerve-trunks, dorsal, dorso-lateral, 

 and ventral, which are connected by numerous commissures. The two 

 apertures of the excretory system are placed far forward on the dorsal 

 surface. The reproductive apparatus has a single orifice from the 

 cloaca, into which the ejaculatory duct and vagina open ; there are two 

 pairs of lobed testes, vitelline glands which are imperfectly segmented, 

 a single ovary, receptaculum seminis, oviduct, and uterus. As in other 

 ectoparasitic Trematodes there is no metamorphosis of the young. 



Trematode in white of newly-laid Hen's Egg.* — Dr. E. Linton 

 records the presence of Distomum ovatum Rudolphi in the white of a 

 freshly-laid hen's egg. The presence of this common avian parasite in 

 this position is not hard to explain ; its favourite place is the bursa 

 fabricii, and an individual may well penetrate occasionally one of the 

 passages which communicate with the cloaca. The creature is known to 

 sometimes make its way into the oviduct, and if it should pass beyond 

 the shell-forming glands when an ovum is in transitu, it might easily be 

 enveloped in the glairy albumen which exudes from the glands; the 

 subsequent deposition of the shell would not be interfered with. 



Lateral organs of Nemerteans.f — Herr E. Devoletzky gives the 

 complete statement of his investigations begun in 1879. 



After some remarks on the methods used, and a review of former work 

 on the subject, he describes shortly the characteristic head-furrows of 

 Nemerteans, and then treats at length the side organs of Terebratulus 

 fasciolatus in particular, and the other Schizonemerteans in general. 

 Drepanophorus is the type of the Hoplonemerteans and these are also 

 described in general. Carinella is next treated in detail, and the results 

 of the investigation are correlated in conclusion. The occurrence of side 

 organs in all three groups of Nemerteans leads to the conclusion that 

 these are organs of special sense, and their considerable importance is 

 shown by their complex structure and their very general occurrence. 

 In forms before thought to be without them, careful search has revealed 

 their existence, and it is probable that if not always persistent, they are 

 present during some part of the life of every species. 



In the simplest form {Carinella annulatd) a simple inpushing of the 

 outer skin is connected with the central ganglia by fibres which break 

 through the inner skin. In C. polymorpha a large opening in this inner 

 skin forms a passage from the more developed canal to the " brain " 

 into which, in C. inexspectata, the canal itself extends directly. In all 

 the higher forms a part of the central nervous system breaks through 

 the body-wall to meet a specialized and inpushed portion of the epithe- 

 lium. These side organs are compared with similar sense organs in 

 other groups of the animal kingdom, especially water-inhabiting ones. 

 Some Annelida and Mollusca are referred to in particular. Side organs 

 cannot be considered to have sight, hearing, or touch as function. Smell 

 and taste are possible since the media in which they work, water and 

 moist air, could convey chemical stimuli to the richly ciliated canals, 

 and to the grooves and furrows of the head. The author does not 

 presume to advance any further hypothesis. 



* Proc. U. S. Nat. Mus., 1887, pp. 367-9. 



t Arbeit. Zool. Instit. Uuiv. Wien, vii. (1887) pp. 23B-80 (2 pis.). 



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