428 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Nerve-Cord of the Earthworm.* * * § — Herr B. Eriedlaender reasserts 
his conclusion that the “ giant-fibres,” or “ Leydig’s fibres,” were rightly 
interpreted by Leydig as medullated nerve-fibres. He has some strong 
criticism of the fallaciousness of methods (e. g. Golgi’s), the insufficiently 
careful use of which has led experts to call medullated nerve-fibres 
supporting elements ! He has shown and photographed complex ana- 
stomoses between Leydig’s fibres and associated ganglion cells, as also 
with the second root of the double nerves. As to the rest of the nerve- 
cord, he is even inclined to believe that it consists predominantly of 
medullated fibres, in the differentiation of which there are, of course, 
many degrees. It is left an open question whether the sheath of Leydig’s 
fibres is wholly a medullary sheath, but the author inclines to believe 
that there is also a supporting webbed structure. 
Origin of Pigment and Colour-marking in Hirudinea.f — Dr. A. 
Graf has a preliminary notice of his work on this subject, and concludes 
that the colour-marking of these animals is not inherited, but is freshly 
acquired in each individual during fhe period of metabolism. It is 
probable that in many other groups of animals, similar factors have a 
part in the formation of the markings. It is possible that, and it is 
worth while to enquire whether, the arrangement of the other systems 
of organs is not inherited, but freshly acquired in every individual ; in 
other words, the author suggests that but few characters are inherited, 
while the other organs adapt themselves to definite chemical and physical 
laws. 
Nemathelminth.es. 
Ankylostomum Larva in Small Intestines of Cattle.f — In the 
slaughterhouse at Gottingen, Herr Strose found in the small intestine 
of cattle, small nodules which contained Nematode larvae. They did not 
appear very clearly through the serosa, and hence might be easily 
overlooked. The nodules lay in the mucosa, which was much thinned, 
and they were invested with a connective tissue capsule. The contents 
of the nodules were caseous friable detritus, and a small parasite of 
2* 83-3*85 mm. long and 0*16 mm. broad. Sexual organs or their 
indications were not present. The author calls the parasite Anchylo- 
stomum v. Dochmius bovis. Drawings of the nodules and of the larva 
are given in a plate. 
Cuticular Structures of Nematodes.§ — Dr. A. van Bommel has 
made an investigation into the structure of the cuticular formations of 
Ascaris lunibricoides, A. megalocephala, and A. mi/stax. Unfortunately 
his paper consists of so many paragraphs filled with direct references to 
the figures that without the republication of them it would be impossible 
to give a fair account of his observations. 
Chsetognatha of the Bay of Amboyna.|| — M. E. Beraneck has a 
report of the Ohsetognatha collected by MM. Bedot and Pictet in the 
* Zeitschr. f. wiss. Zool., lviii. (1895) pp. 661-93 (1 pi.). 
t Zool. Anzeig., xviii. (1895) pp. 65-70. 
t Zeitschr. f. Tiermed. u. vergleich. Pathol., xxi. pp. 110-4. See Centralbl. f. 
Bakteriol. u. Parasitenk., l te Abt., xvii. (1895) p. 537. 
§ Arbeit. Zool. Zoot. Inst. Wiirtzburg, x. (1895) pp. 191-212 (1 pi.). 
II Rev. Suis. Zool., iii. (1895) pp. 137-59 (1 ph). 
