598 a. ]i. hiv'KW A\i» w. UK morgan. 



right vulve, nuirks roughly on the surface a point at which 

 the shell may be bored without damage to any organ. ]iut 

 as the animal gapes when removed from its tank, it is easy 

 to slip a cork between the valves and select a spot by 

 inspection. 



The holes were drilled in the convex or right valve by an 

 ordinary dentist's drill, the head of which was prevented fron> 

 penetrating too deep by a lapping of thread. 



The spot selected for drilling was sterilised with a saturated 

 solution of coiTOsive sublimate, washed off with a solution of 

 hydrogen peroxide (30 vols.) or distilled water, care being 

 taken not to allow any of the sublimate to run between the 

 valves. The transplanting needle was then introduced to the 

 required depth, slightly withdrawn, and its charge projected 

 into the channel. The hole was then thoroughly dried, and 

 stopped with sealing-wax. If the drying is thorough the wax 

 will adhere after the animal has been returned to the tank. 

 It would, of course, have been possible to implant directly 

 into the muscle through the opening of the valves, but the 

 risks of sepsis would have been greater. 



AVhen required for examination, the shell was opened by 

 cutting the adductor muscle at its attachment to the right or 

 convex valve, and a portion of the muscle containing the 

 implanted material removed. This was fixed by three or four 

 hours' immersion in Gilson's fluid, then thoroughly washed, 

 passed through the alcohols, cleaned in xylol, and embedded 

 in paraffin wax. It was then cut into serial sections eight 

 m thick. 



Delafield's hasmatoxylin, followed b}' Yan Gieson's stain, or 

 Benda's iron mordant and htematoxylin were used for staining. 



Besciuption of the Tissues of Pecten maximus involved- 

 IX THE Experiments, and the Nokmal Process of the 

 "Clotting" of the Blood. 



The adductor muscle of Pecten maximus consists of 

 two portions, bound together by the same sheath of couuec- 



