TECHNIQUES 355 



Adhesion is therefore by the naked endoplasm. Sheering of one 

 animal against the other promotes fusion, as if fibrous proteins 

 were then stretched out to expose free bonding points. Even if 

 firm union is achieved at only one point, this is sufficient; for 

 fusion will soon spread throughout the whole wound area. 



Large fusion masses are produced by repeating the simple 

 grafting of 2 stentors. To a fresh cut in a joined pair another cut 

 animal is added, and so forth. If masses of 50 or more stentors are 

 desired, I stop occasionally to give both the mass and the operator 

 a rest, washing the specimen free of methyl cellulose by transfer 

 into culture medium where it remains until grafting is continued. 

 If broad adhesion is not secured and parts are left dangUng or 

 projecting, there is likelihood that the separate individualities will 

 later pull free. With a blunt needle I therefore poke protruding 

 heads and tails into the mass to give a compact form with uniform 

 surface. Large masses may be kept in a fruit-canning funnel closed 

 with bolting silk to permit fluid exchange with a Stentor culture 

 in which the receptacle is immersed (Fig. 97D). Pigmented masses 

 are then easily found and pipetted into block-cells for examination 

 under the microscope. 



To graft a patch of ectoplasm onto another stentor, the desired 

 area is cut from one, using the granular stripe pattern as a guide, 

 but the patch is not entirely isolated and the remainder of the cell 

 is now used as a handle, impaling it with the glass needle and 

 carrying the patch to the host, in which a fresh incision has just 

 been made and opened. Adhesion is accomplished by pressing the 

 cell remainder into the cut opening, fusion spreading to the critical 

 patch; but before secure union is eflFected a tug on the cell 

 remainders orients the patch in place and excess parts are then 

 cut off. In this way the patch is grafted in the desired position 

 without injury from contact with the needle (Fig. 98B). 



Similarly, if stentors are to be grafted as heteropolar telobiotics 

 the heads are first cut loose like the lids of flip-top boxes and 

 fused by thrusting them together, whereupon the union extends 

 to the cell bodies, and the heads are then excised (Fig. 98c). The 

 bodies of the animals have then not been touched with the needle 

 and their individual stripe patterns remain wholly normal. An 

 obvious modification of this procedure is used for making head-to- 

 tail tandem grafts or tail-to-tail telobiotics. 



