June 18, 1915] 



SCIENCE 



the capsule and attached at its other end to 

 the under surface of a cork fitting the phials 

 containing the reagents. The wire should be 

 of such a length as to just permit the flow of 

 the reagent through the two holes in the 

 capsule when the cork is tightly fitted into the 

 phial. To place the objects to be imbedded in 

 their shellac-gelatine container I take a glass 

 rod drawn out to a desirably fine point and 

 dip it into a celloidin solution of gelatinous 

 consistency (12 per cent, celloidin in 80 per 

 cent, alcohol). A little of the celloidin will 

 cling to the point of the rod, which is then 

 allowed to come in contact with the stock of 

 material to be dehydrated, in my case sea 

 urchin eggs. A number of these eggs will 

 cling to the sticky mass, which can be easily 

 washed into the bottom of the prepared capsule. 

 Then it is a simple matter to run the eggs 

 through the reagents. One only has to trans- 

 fer them by taking the cork from one phial 

 and carrying it over to the next. They may 

 first be washed in water and weak alcohol as 

 the outside coating of shellac is insoluble in 

 water and weak alcohol and hence prevents 

 the dissolving of the gelatine. By the time 95 

 per cent, alcohol has been reached the shellac 

 has dissolved away, but in this medium the 

 gelatine is insoluble and so the objects are 

 safely retained. They can be cleared in xylol 

 and left in melted paraJfin to permit thorough 

 infiltration. When ready for the final im- 

 bedding one can easily hold the capsule out 

 of the phial by means of the cork to which it 

 is attached, and slowly drop melted paraffin 

 into the mouth of the capsule with a pipette, 

 all the time blowing on the capsule to hasten 

 cooling. The paraffin will cool quickly and 

 plug up the two drain holes and form a solid 

 cylinder. Then one may detach the capsule 

 from the wire and place it in water where the 

 gelatine soon dissolves, leaving a solid form of 

 paraffin with the eggs imbedded in the end of 

 it. To assure being able to see the eggs one 

 may place the capsule during the dehydration 

 process for a few minutes in borax carmine, 

 which will stain the objects red and thus en- 

 able one to see them through the rest of the 

 process. After being sectioned the carmine 

 may be decolorized with acid alcohol. 



This method removes the danger of losing 

 the objects when transferring them from the 

 various solutions with a pipette. The drop of 

 celloidin assures their being held in a compact 

 mass and in most cases raises the bodies far 

 enough from the floor of the capsule so that 

 the rounded end may be sliced off without 

 cutting away the objects and thus give a flat 

 surface to section from. To be absolutely sure 

 of this one may prepare his capsules with flat 

 bottoms before imbedding. This is done by 

 cutting off the round end and attaching a flat 

 sheet over the bottom with liquefied gelatine 

 and cementing it with shellac. Or again after 

 the objects are imbedded in the round end of 

 the capsule they may be sliced out and reim- 

 bedded in a Lefevre watch glass as suggested 

 by Metcalf.* 



This method will, I am sure, prove useful 

 to any one having much imbedding to do, of 

 minute objects. It has the advantages of being 

 extremely simple, rapid and reliable. 



Paul Ashley West 



Baltimore 



SOME REASONS FOR SAVING THE GENUS 



As there seems to be something of a lull at 

 present in the vexatious controversies over zo- 

 ological and botanical nomenclature, I fear 

 that I run the risk of being branded as a wan- 

 ton mischiefmaker if I seek to reopen the sub- 

 ject in these columns. However, no one can 

 say that the evils complained of are likely to 

 diminish much in the near future. And 

 furthermore, it has always seemed to me that 

 one of the most flagrant of these evils has 

 scarcely been complained of at all, at least in 

 the public discussions regarding nomencla- 

 ture. Complaint has been made, bitterly 

 enough at times, of the constant changing of 

 specific names, resulting from a rigid en- 

 forcement of the law of priority. In reply, it 

 is contended, and with some plausibility, that 

 such changes will cease automatically when 

 the antiquarian has finally accomplished his 

 task. 



But there is another perennial source of 



* Loo. cit. 



