KONGL. SV. VET. AKADEMIENS HANDLINGAE. BAND 35. N:0 2. 69 



Eberth^) seems to have recognized similar structures in a species of Leptosomatiuii 

 (his Phanoglene bacillata), though he put a difterent interpretation upon what he saw, 

 and called the structures »skin-glands» (Hautdriise). It must be admitted that the recogni- 

 tion of their real nature is not so easy in the marine species as it is in Dorylaimus 

 stagnalis. In this latter their nature scarcely admits of a doubt; but the homology of 

 the structures to be seen in this animal with the almost similar structure which may 

 be detected in many of the marine species, as well as in the Trichosomata, is also un- 

 questionable. I have found these channels made much inore apparent after the integument 

 has been swollen somewhat, and rendered more transparent by immersion of the animals 

 in strong glycerine for about twenty-four hours. Although only get detected in the 

 larger species, I suspect these pores exist in a considerable proportion of the free Nema- 

 toids. There seems to be however, evidence to show that none such are present in the 

 representatives of the four genera Tylenchus, Cephalobus, Aphelenchus and Plecius. Con- 

 cerning the species of these genera I shall have to speak further on, and also of the 

 probable use of the integumental channels to those species in Avhich they exist. 



In one only of the parasitic Nematoids have I seen a very close approximation to 

 this arrangement of the integumental channels, and that was in Heterakis acunnnata 

 from the frog. In this animal similar integumental pores may be seen, apparently in 

 single filé, along the lateral aspects of the body (Plate XXII, tig. 12) about V280" apart. 

 On the caudal extremity of the males these seem to be still more numerous and scattered 

 över the surface generally, in addition to the well-marked ventral suckers met with in 

 the same individuals (Plate XXII, fig. 13 c). But in the genera Trichosoina and Tricho- 

 cephalus such pores are extremely numerous, and give rise, more particularly in the 

 species of the latter genus to an altogether exceptional appearance which has long been 

 a puzzle to anatomists; although, on the other hand, in many species of the genus 

 Trichosoma there is a much closer resemblance to what we meet with amongst the free 

 Nematoids.» 



Ich brauche wohl kaum hervorzuheben, dass die »integumental pores» öder »channels» 

 fUr sich allein ziemlich schwer zu verstehen sind. Sie können nur als mit irgend welchen 

 anderen Organen verbunden begreiflich sein. Da liegt es, wie ich schon gesagt habe, 

 wohl am nächsten, zu glauben sie seien Ausfuhrungsgänge fiir Drusen. Es giebt aber 

 auch eine andere Deutung, die ich fur vielleicht noch wahrscheinlicher halte. Wir können 

 es nämlich mit Nervenendigungen zu thun haben, die niedrig sind und mit Borsten öder 

 hohen Papillen nicht in Verbindung stehen. Solche sind denn auch raehrfalls beschrieben. ^) 

 Eine Stiitze fur die letztere Vermutung liegt meiner Ansicht nach darin, dass die von 

 Bastian bei den parasitischen Nematoden, z. B. Ascaris lumhricoides, beschriebenen »inte- 

 gumental pores» (loch wohl als von Nervenendigungen hervorgerufen anzusehen sind, und 

 zwar sowohl die vorderen als besonders die hinteren sog. »caudal pores». Butschli be- 

 schreibt^) auch bei ebendemselben Dorylaimus stagnalis Duj. wohl dieselben »integu- 



^) Untersuchungen ilber Nemat., pp. 8 u. 19. Taf. 2, Fig. 1. 

 2) Siehe z. B. diese Årbeit Taf. 1, Fig. 4. 



') Beitr. zur Kenntiiiss der freilebenden Nematoden. Nov. Act. C. L. C. G. Nat. Cur. Vol. 36. S. 25, 

 Tafelerklärung S. 124, Taf. 17, Fig. 4 0. 



