100 EEPORT 1889. 



made by heating the tubing and pulling out to arm's length. Most of 

 the narrow part thus made is broken off and thrown away, only two to 

 three inches of it being allowed to remain intact. This is bent at right 

 angles with the original tubing in a low alcohol flame, and then again 

 drawn out in the alcohol flame to capillary size. 



5. All corners had better be rounded ofl" in a Bunsen flame. 



Thanks to the differentiator, I have lying on slides, ready for investi- 

 gation, about 3,000 excellent specimens of free-living nematodes, about 

 half in glycerine and half in balsam. In spite of the fact that many of 

 the species are delicate little creatures only half a millimetre long, the 

 shrinkage is in the strict sense of the word scarcely perceptible. 



What I liave said concerning nematodes applies also to such infusorians, 

 diatoms, desmids, and mould-filaments as I have come across among my 

 specimens (therefore killed at the same time and treated in the same 

 manner as the nematodes). 



I find that vorticella, young platyhelminthes, rotifera and infusoria, 

 which generally defeat the process of fixation by untimely contractions, 

 become limp and manageable with sublimate, &c., if they are first 

 changed to 30 per cent, alcohol (or weaker) in the differentiator. 



The instrument may be found of general application. It recommends 

 itself on account of its simplicity. Anyone can make it in a few minutes' 

 time. 



I shall make the results of my studies while at Naples the subject of 

 a paper shortly to be published. 



I desire to take the opportunity at the end of this report to express 

 my hearty thanks to the Committee of the British Association for the 

 profit and pleasure I have enjojed in the use of a table at a zoological 

 station so happily situated and skilfully managed as that at Naples. 



II. Eeport on the Occupation of the Table, by Mr. F. Ernest Weiss. 



I occupied the table of the British Association at the Zoological 

 Station at Naples from January 1, 1889, to May 1, 1889, and dur- 

 ing the whole of my stay everything that could facilitate my work 

 was done by the authorities. As the eggs of Sepia and Loligo, on 

 which I had intended chiefly to work, were still scarce, I started 

 on some anatomical investigations of Amphioxus, and was able to confirm 

 the observations of Professor Lankester, published while I was still 

 working at Naples. 



Having the living material at hand, I also undertook some observa- 

 tions with regard to the currents of water passed through the pharynx 

 and gill-chamber, and some physiological experiments on the absorption 

 of food particles and on the excretion. Carmine granules were readily 

 taken up in a finely divided state by the intestinal epithelium, and the 

 carmine was found later in the vascular system no longer as granules, 

 but colouring the corpuscles, and, to a certain extent, the liquid. 



This fact enabled me to confirm the statements of Schneider, which, 

 according to Professor Lankester, needed confirmation — namely, that the 

 dorsal aortas send off lateral vessels both into the j'fimary and into the 

 secondary bars of the pharynx. 



With regard to the excretion I did not arrive at any definite results, 

 owing partly to the lack of time, as Dr. Eisig pointed out that in the case 



