BY R. VON LENDENFELD, PH.D. 971 



Gastrovascular System. 



The stomach and the va-scular system stamps our animal as a 

 real Beroid. The stomach is in no degree influenced in its form 

 by the flaps but has the simple shape of a cone or sack, I 

 was able to observe the peristaltic movement of the stomach. 

 Only one stricture occurs at a time. It begins above the mouth 

 jirogresses quickly upwards and reaches the aboi'al end in about a 

 second and a half. The stomach is thereby constricted to a fourth 

 of its usual diameter. As soon as the contraction has reached the 

 end, a fresh one commences at the mai-gin of the mouth. 



This pei'istaltic movement can be reversed and I consider this 

 as very important. If the animal is not killed at once but is 

 allowed to lie in slowly acting reagents this reversed peristaltic 

 movement can easily be observed. 



If a Neis dies slowly in a mixture of 16% alcohol, 16% glycerine, 

 5% corrosive sublimate and 67 "5% sea water, the reversion of the 

 movement of the stomach described above, sets in soon after the 

 animal is placed in this preparation. The vomiting movement at 

 first recurs rapidly and afterwards when the animal is near death 

 it can be brought on again in a less degree by mechanical irritation. 



The stomach is as Agassiz (1, p. 74) at length describes, extraor- 

 dinary mobile and our Neis can without diSiculty swallow animals 

 larger than itself. 



The Vascular System. 



The Vascular System of the Gallert consists of eight stems 

 which spring from the stomach in the same manner as Chun (3, p. 

 bQ and elsewhere), describes it in the case of Bero6. The vascular 

 reticulation difiers m as far from that of Bei'oe (3, p, 57) that it 

 forms a continuous network, and is not divided into two separate 

 vascular systems. 



The vascular reticulation of Neis is much more highly developed 

 than that of Beroe. Whilst in Beroe the canals form a reticulation 

 of scarcely more than one superficial layei*, in Neis the network 

 extends in three dimensions from the superficial, tangental canals, 

 branches extend centripetally and pervade the gallert reaching to 



