THE CHLOROPHYLL-BODIES. 45 



become frothy; and it is also sometimes the case that it moves in a 'streaming' manner, 

 and in the interior of the firmer enveloping layer a circulation sets up, as in a celP. 

 The nucleus always remains enclosed in the substance of the protoplasm ; if this latter 

 forms vacuoli or assumes the condition of circulation already described, the nucleus 

 remains enveloped in a coating or in a thicker mass of protoplasm, which is connected 

 M-ith the parietal protoplasm-sac by the lamellae lying between the vacuoli as well as by 

 the current-threads. The nucleus apparently follows passively the displacements and 

 wanderings of the portion of protoplasm in which it is enveloped; it also undergoes 

 changes of form under the pressure and progress of the moving mass, which proceed 

 under the eye of the observer. 'During the movement,' says Hanstein {I.e. p. 226) 



admirably, ' the bands of protoplasm are and remain very tightly stretched, so that 



the envelope of the nucleus is drawn out by them into sharp angles. It looks as if the 

 nucleus (together with its envelope) \vere towed about like a ferry-boat by ropes 

 stretched across. But since during this towing the bands themselves alter their direction 

 and form, it is self-evident that the envelope of the nucleus must also change its form. 

 But not only the envelope, but also the nucleus itself, does this. This latter is never 

 spherical or of any similarly regular form during the time of its wandering, but is irregu- 

 larly elongated, and usually in the direction of its motion at the time.' This change in 

 the form of the nucleus may also be recognised from the displacement of the nucleoli 

 within its mass. 



Sect. 6. The Chlorophyll -Bodies and similar protoplasmic Struc- 

 tures I— Chlorophyll, the green colouring matter so generally distributed through 

 the vegetable kingdom, is always united to definitely formed portions of the proto- 

 plasmic body of the cells in which it is found ; these green-coloured portions of 

 protoplasm may, in contradistinction to the colouring matter itself by which they 

 are tinged, be designated Chlorophyll-bodies. Every chlorophyll-body consists then 

 of at least two substances, the colouring matter and its protoplasmic vehicle ; if the 

 former is removed by alcohol, ether, chloroform, benzine, or essential or fatty oils, 

 the latter remains behind colourless. The colouring matter contained in each 

 chlorophyll-body is itself only extremely small in quantity; after its removal the 

 protoplasmic ground-work retains not only its form but also its previous volume. 

 The latter is always a solid soft body containing extremely small vacuoli, in 

 which the colouring matter is generally completely, though not always uniformly, 

 distributed. 



Chlorophyll-bodies arise in the young cells by the separation of the protoplasm 

 into portions which remain colourless and others which become green and sharply 

 defined. The process may be supposed to take place by very small particles of a 

 somewhat different nature originally existing in or being distributed through the pre- 

 viously homogeneous protoplasm, then collecting at definite places and appearing as 

 separated masses. The grains of chlorophyll which arise in this manner always re- 

 main imbedded in the colourless protoplasm in a similar manner to the nucleus ; they 



^ In young hairs of Hyoscyamus niger, according to A. Weiss in the Sitzungsberichte der kais. 

 Akademie der Wissenschaften, Vol. LIV. Vienna, July 1866, 



2 H. von Mohl, Bot. Zeitg. nos. 6 and 7, 1855.— A. Gris, Ann. des Sci. Nat. Ser. IV. Part VII. 

 p. 179, 1857.— Sachs, Flora, p. 129, 1862; p. 193, 1863.— Sachs, Haiidbuch der Exper. Physiol, der 

 Pflanzen, § 87, Leipzig 1863.— Hofmeister, Die Lehre von der Pflanzenzelle, § 44, Leipzig 1867. 

 — Kraus, Jahrb. fiir wissensch. Bot. VIII. p. 131, 1871. 



