602 DEVELOPMENT OF THE ECHINOCOCCUS-BLADDEE. 



larger bladders after staining, had neither in nature nor arrangement 

 the slightest resemblance to that network. They appeared to be 

 longitudinally extended, thin, sharply defined fibrils (0-001 mm. 

 thick), which crossed in different directions, never uniting so as to 

 form a closed layer or net, but always remaining separate, and at most 

 turning aside from their former course at the points where they divide. 



Whether this peculiar network has any connection with the 

 ramified granular cells which I have already described in the larger 

 &hinococcus-hl&Mevs from my second experiment, or is perhaps even 

 formed from them, I must leave undecided, as also the question of its 

 physiological significance. In this connection I can only remark 

 that in one case, in which the still headless UcMnococci measured 

 from 12 to 20 mm., I sought in vain for the network, but again found 

 the previously observed cells with ramified processes, and noticed 

 that these were united here and there into real nets. It is true that 

 the appearance of the network in the two cases was very different, 

 and I must also own that the last-mentioned UcMnococci were by no 

 means in so good a state of preservation as the former ones. Not 

 only was their parenchymal layer separated in some places from the 

 cuticle, but they were without the drop-like bladders, which, in other 

 specimens, lay upon the inner surface of the cellular layer, and in 

 some places they even exhibited distinct holes, wliich could be readily 

 observed on the cuticle. 



When compared with the usual bladder-worms, the Echinococcus 

 consequently exhibits a whole series of unexpected peculiarities. It 

 is true that on the whole the analogy with the bladder of the Gysti- 

 cerci is unmistakeable, but, on the other hand, the immense thickness 

 of the cuticle, the absence of a powerful musculature, the slow growth, 

 and the late development, not only of the tape-worm head but of the 

 vascular system, and of the calcareous corpuscles (which, I may add, 

 are only found in specimens of at least 8 mm. in diameter), present 

 differences both numerous and important. Whether these peculiarities 

 are mutually dependent on each other, and whether they have any 

 connection with the thickness and firmness of the surrounding con- 

 nective-tissue capsule, or with the well-known peculiar structure of 

 the Uchinococcus-head, we shall not further investigate. It is sufficient 

 to indicate generally the possibility of such a connection. 



In conclusion, I may remark that, in spite of its thickness, the 

 cuticle of the Echinococcus possesses a very considerable capacity of 

 imbibition. If the extracted bladder be placed in water or spirits of 

 wine, it is observed that after a short time the parenchyma detaches 

 itself more and more extensively, and ultimately becomes a bladder, 

 suspended freely ins^^yji^|^gH(jJ^j^^g^^been depicted by Kuhn. 



