ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 427 



the elements of the surrounding parenchyma which become fused with it. 

 In consequence of this it is difficult to determine whether the several 

 elements which become converted into the elements of the ovary arise 

 from the primary rudiment, or from the parenchyma. 



Put shortly, we may say that the development of the generative 

 organs commences with the differentiation of the efferent apparatus ; the 

 germ-producing organs appear later, and, in correspondence with their 

 position in the mature proglottis, either more or less closely connected 

 with the rudiment of the efferent apparatus, or quite independently of 

 it. The information which we have as to the mode of development of 

 the generative organs of other Platyhelminthes is too slight and too 

 contradictory to enable the author to make any useful comparisons 

 between them and the Cestoda. 



Interesting Specimen of Taenia saginata.* — Dr. J. G. Stanton 

 gives an account of a specimen of Taenia saginata, which is remarkable 

 for its unusual length and for the malformations it presents. The total 

 is estimated as 1061 joints in a chain about 7*655 metres long; with 

 this remarkable length the number of joints is rather below than above 

 the average. There is an extra joint which is heart-shaped, and has its 

 inner border resting in a semicircular depression at one side of the 

 chain, opposite the point of union of two adjoining segments of large 

 size. Its free border extends some distance beyond the lateral margins 

 of the two adjacent joints, and terminates in a slightly rounded point. 

 The largest number of successive joints with genital foramina on the 

 same side is six. 



Generative Apparatus of Diplozoon paradoxum.f — Dr. E. Zcller 

 has investigated the structure of the generative apparatus of Diplozoon 

 paradoxum. The male apparatus consists of a single testis with one 

 duct, while the female organs are the ovary with its duct, the yolk- 

 gland with its duct, the canal of Laurer, the uterus and oviduct, and an 

 external papilla. 



The testis is placed in the hindermost part of the hind-body, is of 

 considerable size, and has a rounded slightly lobate form. There is a 

 fairly well-developed investing membrane within which are very clear 

 cells with a diameter of 0*015 mm., and of an irregularly polyhedral 

 form. The nucleus is of an extraordinarily large size, its membrane is 

 very thick, and the homogeneous fluid contains distinct nucleoli. The 

 spermatozoa are long. 



The ovary occupies the anterior half of the hind-body ; it is 

 elongated, and curved in such a way that its commencement and termi- 

 nation lie close to one another, as van Beneden has already observed. 

 The youngest are very small and indistinct ; as they pass forwards they 

 increase in size and finally become quite large. The ovule, when ready 

 to leave the ovary, has a thick and very elastic envelope, a finely 

 granular yolk, a germinal vesicle filled with clear fluid, and a germinal 

 spot in which there is one large or several smaller cavities. Its duct is 

 proportionately narrow, but very extensile. The yolk-gland is a large 

 organ, and its rounded lobules fill up the greater part of the fore-body ; 

 its constituent cells are more or less rounded. The number of lobules 

 is so extraordinarily large, and are so closely packed, that it was not 



* Zool. Anzeip., xi. (1888) pp. 94-5. 



t Zeitschr. f. Wiss. Zool., lvi. (1888) pp. 233-9 (1 pi.). 



