316 President's Address. 



multiplication of tho araylum-bodies aii'l thfi forking of the proto- 

 plasm threads, the amylum-bodies so connected may be in different 

 spires of the chlorophyll-band. In the angles of the forks of the 

 branching protoplasmic threads there is usually visible in strongly 

 growing Spirofpjra filaments a thickening of the substance of the 

 thread in which a vesicle, perhaps a kind of amylum-body, lies. 

 There is, then, in Spirogyra, a direct connection through the threads 

 between the amylum-bodies themselves, and also between them and 

 the nucleus. 



These very definite anatomical relationships render Spirogyra a 

 very favourable subject for future investigation of the condition in 

 which hypochlorin exists in the fresh cell when unacted on by acids. 

 It is not, indeed, difficult to observe in its chlorophyll-bands before 

 they are treated with acid, signs betraying the existence of some 

 peculiar substance. If a cell of Spirogyra erassa, or other large 

 species rich in hypochlorin, be slightly injured, either by mechani- 

 cal pressure or by warming (up to 30°-40° C. according to the 

 species), so that but little disturbance of cell-content is produced, 

 there are seen in the projections at the edge of the chlorophyll-bands 

 and beside the amylum-bodies, that is, at the exact position where 

 hypochlorin becomes visible when an acid is employed, large clear 

 vacuole-like spaces filled with strongly refractive oil-like matter. 

 These, which have not been hitherto generally noticed, differ from 

 the small fat-particles abundantly distributed through the bands by 

 their larger size, more fluid content, and the possession of a limiting 

 pellicle. A slight contraction of the band in breadth is associated 

 with their appearance, and the projections on the edge of the band 

 disappear. After very slight warming the large vacuoles may be 

 readily observed at the edge of the band to rupture their skin, and 

 their fluid content is disseminated in the surrounding protoplasm 

 lining the cell "wall. In large species of Spirogyra a spontaneous 

 coalescence of the vacuoles may often be witnessed. 



The position of these vacuoles leads to the conjecture that it is 

 their oily content which forms the hypochlorin excrescences, a con 

 jecture quite conformable with the easy destructibility of hypo- 

 chlorin in green tissues. For this accumulation of oily matter in 

 vacuoles, the ready escape of the same, and its dissemination in the 

 protoj)lasm under slight mechanical or thermal influences, affords an 

 explanation of those cases where the hypochlorin reaction is absent 

 or suppressed, and further explains the results, now to be described, 

 that follow when green tissues previously warmed in water are 

 treated with dilute acids. After such treatment the hypochlorin 

 reaction is suppressed. 



If a tissue which has been warmed in water, and in which the 



