234 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of fluids and also prevented loss of the animals. When this manipula- 

 tion was finished the test tube was broken and the paraffin block 

 extracted. It was found to be important to keep the animals in 

 one- third alcohol for 10 minutes, and for 6 hours in 50 p.c. alcohol, and 

 to carry the imbedding through slowly. Some difficulty was experienced 

 in making sections, as the carapace was easily fractured though the internal 

 parts were easily manipulated. The best stain was Heidenhain's iron- 

 hsematoxylin. 



Demonstrating the Presence of Indigo.* — H. M. Leake, for his 

 investigation on indigo-yielding plants, placed pieces of the material in 

 the following mixture : acetic acid 2 c.cm., sulphuric acid 1 c.cm., ammo- 

 nium persulphate 0*5 grin., water 100 c.cm. According to size the pieces 

 remained in the fixative for from 4-12 hours. They were next placed 

 for 3-4 days in 50 p.c. alcohol, changed daily. The sections varied 

 from 4-12 /x in thickness. They were stained in Delafield's hsematoxyliD 

 and decolorised with hydrochloric acid alcohol. They were next placed 

 for an hour or so in 1 p.c. Griibler's water-soluble eosin ; then absolute 

 alcohol, xylol, and balsam. The indigo contents of the cells were clearly 

 shown. 



Demonstrating the Structure of Nucleoli and Chromosomes.! — 

 T. Martins Mano used Phaseolus vulgaris and Solanum tuberosum, the 

 grains and tubercles of which were germinated at different temperatures. 

 The material was fixed in Hermann's, Bouin's, or Perenyi's fluid, the 

 first mentioned giving the best results. Sections from 5-7£ \l thick 

 were stained with Heidenhain's hsematoxylin, either alone or with Congo 

 or Bordeaux red, with light green and safranin, with Delafield's hsemato- 

 xylin and picric acid, and other dyes. 



Heidenhain's heeinatoxylin gave the details of nuclear structure more 

 clearly than other solutions. 



Studying the Nervous System of Asterias rubens.J — P. Meyer 

 obtained the best staining results from the use of molybdic acid hsema- 

 toxylin and Malory's heeinatoxylin after fixation in sublimate acetic acid 

 (saturated solution of sublimate in hot sea-water, 100 parts, and 2 parte 

 of acetic acid). An excellent fixation and staining reagent was found 

 in a mixture of 1 part of 1 p.c. osmic acid and 3 parts of the above- 

 mentioned sublimate acetic acid. After 12-15 hours the objects were 

 washed in sea-water for 6 hours and then for a similar period in pyro- 

 ligneous acid, followed by another course of sea-water. The sublimate 

 was removed in iodine alcohol, and after dehydration in alcohol the 

 material was passed through chloroform to paraffin. 



Observations on the Structure of Pleistophora periplanetae.§ — 

 W. S. Perrin examined the living plasmodia inhabiting the malpighian 

 tubules in normal salt solution. Films were prepared by cutting the 

 tubules into small pieces and spreading them on a coverslip. After 



* Ann. Bot, xix. (1905) p. 297. 



t La Cellule, xxii. (1905) pp. 57-76 (3 pis.). 



J Zeitschr. Wiss. Zool., lxxxi. (1906) pp. 96-144 (2 pis.). 



§ Quart. Journ. Micr. Sci., xlix. (1906) pp. 615-33 (2 pis.). 



