354 SUMMARY OF CURRENT RESEARCHES RELATING TO 



but of cornein, an albuminoid probably related to the supporting tissue 

 proteins of other animals. It is maintained that the posterior part of 

 the oesophagus has an excretory function, waste products passing through 

 the wall into the surrounding accessory tissue, and thence into the 

 lateral canals. The muscular system is dealt with at length. The chief 

 food is the blood of the host, and the fluid in the body of the Nematoda 

 is red, without doubt because of some product from the ingested blood. 

 Only the anterior ovary and oviduct are developed ; the latter contains 

 a seminal vesicle ; the species is viviparous. The nervous system con- 

 sists of a nerve ring, anterior ganglia, longitudinal nerves and posterior 

 ganglia. The anal ganglion is simple, and in the male there are large 

 posterior lateral ganglia which supply the anal papillae. But these are 

 only a few of the general results of an elaborate and well-illustrated 

 study. J. A. T. 



Platyhelminthes. 



Tapeworms of Vertebrates. — 0. Fuhrmann {MT. Nat. Ges. Bern., 

 1917, xii-siii). A general discussion with many interesting points. 

 In 0. von Linstow's Compendium (1881)) there were listed about 105 

 species of tapeworm from mammals and 230 from birds ; now there are 

 about 250 from mammals and 650 from birds. Of the latter 250 have 

 been described by Fuhrmann and his students. Representatives of 74 

 genera are found in birds, 30 in mammals, 12 in both. Fuhrmann 

 recognizes nine families of Tapeworms. Twenty-three years' work leads 

 this authority to say that a particular species is always restricted to one 

 particular group of birds, and many genera (44 out of 72) are represented 

 only in one group of birds. This shows notable specificity. J. A. T. 



Respiratory" Metabolism in Planaria. — G. D. Allen {Amer. 

 Journ. Physiol., 1919, 48, 93-120). The oxygen consumption by 

 Planaria agilis can be reduced to 30 p.c. of the normal rate by potas- 

 sium cyanide in a concentration as low as 0'0002 molecular. Lower 

 concentrations cause proportionately greater ^reduction than higher con- 

 centrations. There seems to be a residual oxidation amounting to about 

 20 p.c. of the normal which cannot be inhibited by KCN. Worms 

 recover their normal level of oxidations rapidly and completely after 

 removal from the cyanide solutions. The inhibition of oxidations could 

 be attributed only in small part to the cessation of movement which 

 results from the anaesthetic action of cyanide. J, A. T. 



Carbon Dioxide Production in Starving Planaria. — C. M. Child 

 {Amer. Journ. Physiol., 1919, 48, 231-57). During the first few days 

 of starvation the production of COg decreases rapidly ; it continues to 

 decrease more slowly during several weeks : in advanced stages of 

 starvation it increases. The more rapidly starvation, and particularly 

 the reduction of the alimentary tract, occurs, the more rapidly these 

 changes in COg production take place. Fission and regulation accelerate ^ 

 the progress of starvation. Feeding restores the CO^ production very 

 quickly, and it seems that animals reduced by starvation and then fed 

 are physiologically younger than at the beginning of starvation, and if 



