300 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



rotatory about the angle-piece. The clutch when setengages downwards 

 in the toothed-wheel of the rear roller. When the apparatus is in 

 action the band in the case of every section travels just as mnch forwards 

 as the movement in length of a section of the object under treatment. 



As soon as the serial sections have commenced formation their free ends 

 are placed by a paint-brush 'on the band and then left : while the cutting 

 is continued the sections unfold and arrange themselves ribbon-like on 

 the band till they have reached the free end, where they are removed in 

 their entirety. The movement of the knife-block insures the automatic 

 action of the band-gear. The teeth of the wheel are so cut that the 

 clutch slides downwards over them in the back stroke, and engages in 

 them in the forward stroke. 



Some preliminary trials will be necessary to get the exact position of 

 the clutch staff suitable for the section-length, so that the sections may 

 form a perfect ribbon. In order to facilitate this operation the author 

 has designed a special knife adjustment (fig. 112), consisting of a modified 

 knife-clamp and a small block with position screw. A perforated circular 

 disk around which the required movement is to take place is applied to 

 and fixed upon the screw-holder. The shanks of the knife bear 

 corresponding notches in which the disk engages. The small block with 

 the position-screw is set in the groove of the knife-block, and a slight 

 rotation of the position-screw gives the required inclination to the 

 knife. 



Method of Orientating Small Objects for Examination.* — 

 W. F. Cooper and L. E. Robinson contribute a short note on a 



CORK 



PLASTY iNL 



CORH- 



,HN 



Fig. 113. 



method they have found useful in their work on Ixodidea. The 

 method is an improvement on those generally used for the examination 

 of ticks. The authors give the following account of their procedure. 



" In the examination of the appendages and small portions of 

 Arthropods, considerable difficulty is often experienced in fixing them 

 temporarily in a suitable position for observation. This can be over- 

 come by the use of a preparation universally known as ' Plasticine.' 



" A small bead of it is placed on a slide and slightly flattened : the 

 object is then placed upon it, moved into a suitable position, and 

 slightly pressed into the plasticine. 



"We have devised a simple piece of apparatus by means of which 

 the object may be rotated in one plane (fig. 113). A cork is cemented 



* Original communication. 



