Cockayne. — Botanical Excursion to Southern Islands. 237 



the rendezvous of numerous sea-lions. At the time of my 

 visit there were perhaps forty of these large animals on 

 the beach, while others were encountered on the dunes. 

 The heavy bodies of these creatures dragged over the ground 

 must have some effect on the vegetation, especially as 

 they are wont to roll about on the sand. At the present 

 time the sand-dune formation cannot be considered quite 

 a primitive one, since already cattle, and perhaps rabbits, 

 have loosened the sand, so that dunes originally stable are 

 now moving inland, and have already invaded the forest 

 zone, destroying some of its outermost members. This fact 

 is the more interesting because, as will be seen from what 

 follows, the dune-plants are none of them true sand-binding 

 plants, such as Scirpiis frondosus of New Zealand or EhjmiLs 

 arenarius of the Northern Hemisphere, the extreme moisture 

 of the climate, in conjunction with the short periods of sun- 

 shine, keeping the sand sufficiently moist on the surface to 

 promote in many places the growth of a turfy covering, which 

 is quite sufficient to keep the sand from drifting, in the ab- 

 sence of introduced herbivorous mammals. Even where the 

 dunes are quite bai'e the climatic conditions probably would 

 suffice to keep them stable. All the same, the absence of 

 such a widely spread sand-binding plant as Scirpus frondosus, 

 which extends even to Chatham Island, is a matter for con- 

 siderable surprise. 



The dunes are traversed by deep gullies, down which 

 small streams of water flow, the drainage from some swampy 

 ground between them and the "rata forest." Such gullies 

 furnish plant-stations having considerable shade and mois- 

 ture. On the summit of the dunes are great numbers of 

 small stones, said to be part of the excreta of the sea-lions. 

 Musgrave (83, p. 148) refers also to such stones, and states 

 that he found a deposit of them in peaty soil Gift, below the 

 surface of the ground. 



The dune vegetation varies from an open to a quite close 

 formation, this latter appearing as a green sward, even when 

 viewed from some distance (see the dark patches in PL XII.). 

 The open portion of the formation appears, of course, in those 

 places most exposed to sun and wind, and has for its plant- 

 members a species of moss of a dense habit of growth, speci- 

 mens of which I unfortunately failed to procure, stunted Tillaa 

 moschata, Bammcuhis acatdis, and Humex neglectus. As all 

 these spermaphytes are also quite common at various places 

 on the New Zealand coast a detailed description of their life- 

 forms is unnecessary ; suffice it to say that Bumex neglectus 

 and Ranunculus acaulis have both creeping underground 

 stems, those of the former of considerable dimensions, by 

 which they can easily spread in the sandy ground, while the 



