BY 3IARJ0RIE I. COLLINS. 



333 



in that the bead is always vertically elongated and never shield-like. What ap- 

 pears to be tlie normal type of gland is figured in Text-fig. la. There the head 

 is composed of an octant of cells, and is supported by a short stalk of two cells. 

 The stalk may possess two or three cells (Text-fig. la-c), but is often absent 



Text-fig. 7. — (a-d). Gland forms of Acacia 

 armaia in which stalk region is present; 

 e-f, types where stalk is absent, (x 200) . 



Text-fig. 8. — Glandular hair from the base 

 of the phyllode in Acacia pycnantha. 

 (x 200) . 



(Text-fig. 7e-f). The head in the greater number of glands is characterised by 

 vertical and horizontal divisions which vai-y in number and sequence (Text-fig. 

 7h-e). Text-fig. If sliows a new type of gland which has arisen by the omission 

 of the divisions giving i^ise to stalk cells. 



Acacia pi/ctiaiitlia. — In ^1. piicn.antha the glandular hairs are restricted to a 

 Z(me at the base of the phyllode. The mature glands are elongated in form, and 

 show no differentiation into head and stalk region. They are multicellular, club- 

 shaped bodies in which both vertical and horizontal walls are formed ( Text-fig. 8 ) . 

 These glands are of interest in that they resemble the stalkless type of gland 

 found in A. armata (Text-fig. 7/'), and could conceivably have arisen from tliis type 

 by tlie interpolation of further divisions. 



N. 0. COMPO SITAE. 



Resin-secreting glandular hairs are widely distributed in the N. 0. Compositae, 

 and have been recorded by various investigators (1, 4, 5, 6, 7). The most com- 

 mon type of gland is shortly stalked and possesses a head divided by a median 

 vertical wall into two rows of cells. These are recorded for species of AnthemiK, 

 Baccharis, Brachiilaena, etc. (3, p. 460), and have been observed by the writer in 

 Ixudea achiUeoides R.Br., llumea cassinlacea F. v. M., and Helichrysum semipap- 

 posum DeCand. The glands figured by Vogl for a species of CJirysanthemam 

 (see 3, i., p. 458, fig. W3h, after Vogl), evidently represent a transitional stage be- 

 tween those observed by the writer for Helicliri/siim semipappufiiim and I.mdea 

 achiJleiiides. 



Gland Development. — In tliese three types the first transverse division whicli 

 cuts off the rudiment of the gland from the epidermis is followed by a median 



