ARID PORTIONS OF SOUTH AUSTRALIA. 



127 



or aggr^ated into a sympodial type, or it may be a "water-storage" 

 hair, type not given, or a disk hair with multicellular flattened head. 

 Stomata occur on both surfaces of the leaves. Strictly bifacial leaf- 

 structure does not occur in Eremophila. 



Apparently much of the work referred to by Solereder was based 

 on herbarium material. In the present study, also, it has been neces- 

 sary to rely on such material. The following species of Eremophila 

 were observed by the writer at the places named and were subsequently 

 examined: 



Although the list comprises all of the genus that were seen at each 

 of the places named, it does not preclude the possibility that others 

 may have been at each station as well. It will be seen that E. brownii 

 is fairly widespread, while others, as E. rotundifolia, paisleyi, and 

 especially neglecta, have a limited distribution. No species of the genus, 

 however, appears to occur outside of the desert-arid or semi-arid 

 regions. 



In addition to the species of Eremophila as at present understood, 

 the study includes Pholidia scoparia, formerly classed under the genus 

 Eremophila. This species has a greater range than any of those given 

 in the above list and occurs where the rainfall is fairly good as well as 

 where it is relatively small in amount. 



An examination of the leaves of the different species of Eremophila 

 shows not a little diversity as to several morphological features, among 

 which are the conditions of hairiness, the character of the trichomes, 

 the size, the plentifulness as well as the presence of internal secretion 

 glands, the character of the epidermis, the position and other features 

 of the stomata, and, not to extend the Ust, the character of the sub- 

 epidermal tissues. There are also apparent, possibly real, correlations 

 between several of these features which are of interest. 



Resinous secretion organs occur either as hairs or as pockets deeply 

 embedded in the tissues of leaf or stem. In the leaves the pocket 

 glands are usually in the mesophyll, although the position is not con- 

 stant. They are to be found only in the primary cortex of stems. 

 The origin of these internal secreting reservoirs, for such they appear 

 to be, is apparently in dispute. It is maintained on one side that they 

 are schizogenous and on the other that they arise through the breaking 



