THE VICTORIAN NATL'KALIST 



($ 



Bacilli. These forms of life — wlietlier animal or vegetal as yet 

 undeterminable — had previously only been detected in animal 

 fluids, decaying vegetals, and as the governing influence in the 

 various fermentations and zymotic diseases. Their presence in 

 plant tissues adds another interesting bond of nnion between 

 the two kingdoms. 



V^egetable physiology has gained as much from the adoption of 

 micro-chemical methods as it had previously from the use of high 

 powers of the microscope. Double or multiple staining has 

 attained a high degree of perfection, but as Dr. Ralph points out 

 this is not a chemical re-action at all, and is usually a mere stain- 

 ing of the cell walls of particular tissues, and not of their proto- 

 plasmic contents. In search of re-agents which should produce 

 a direct chemical eflect, evidenced by change or production of 

 colour, Dr. Ralph has found one which is remarkably active, 

 neutral molybdate of ammonia. In a paper read before the 

 Victorian Microscopical Society in January last, he gave an 

 account of its action on 120 genera of plants. He carefully pre- 

 pares the solution of the salt by adding excess o£ ammonia to the 

 molybdic acid, and getting rid of the excess by evaporation. In 

 piacing a drop of this liquid on the slide, and drawing it under 

 the cover, tissues of c rtain plants mounted in water immediately 

 show the cell contents tinted with various shades of orange, from 

 palest yellow to deepest red orange. But all plants are by no 

 means alike in their reception of the re-ag'ents, nor are all 

 tissues in the same plant. Dr. Ralph has classified his plants 

 according to the readiness with which they are acted upon, some 

 giving a decided re-action, others a partial or moderate, and a third 

 group no re-action at all. Among the last appear to be most of 

 the Monocotjdedoas experimented on, but Hedychium and the 

 Banana fruit gave most marked results, some of the constricted 

 vessels of the latter taking an almost startling blood-red hue. The 

 members of Myrtacee and Proteaceaj examined, all gave positive 

 results. Of 120 genera, 30 were unaffected, 62 gave a full, and the 

 remainder a partial re-action. Dr. Ralph is hopeful that with more 

 extended experiments, ordinal or generic chai-acters may be recog- 

 nised. He suggests the trial of the re-agent in demonstration of 

 pollen-tubes in style-tissues, and of the hyphre. of endophytal and 

 epiphytal microfungi. 



We hope, as is also the wish of Dr. Ralph, that others will experi- 

 ment on this subject. A careful examination of the action on 

 separate tissues, such as the air-containing cells of an epidermis or 

 of the pith of rushes, the chlorophyll-cells of Marcliantia, or any 

 other green cellular plant, &c., will lead to definite and perhaps 

 valuable conclusions. 



