66 THE VICTORIAN NATURALIST. 



are situated under the 37th degree of south latitude, while the 

 Eastern Alps of Europe lie in 47 degrees north latitude. The 

 last-named mountain-chain is therefore ten degrees further 

 removed from the equator than the first-named, and must, there- 

 fore sliow a proportionate decrease in the j'early temperature, yet 

 the tree-growth extends to higher altitudes in the European Alps 

 than is the case in our Alps. 



An explanation of this fact may be that in the European 

 Alps the forests consist, in the higher elevations, ex- 

 clusively of Conifers, whose dense growth resists more effectively 

 the encroachment of the heavy snowdrifts, and thus affords 

 more protection than is the case with the Australian forest, 

 where the Eucalyptus trees, with their high, slender trunks 

 and open crowns, are further apart, thus providing no 

 mutual protection against the ravages of wind and snow storms. 

 It is this general external difference in the forests which un- 

 doubtedly contributes a great deal to the changed characters of 

 the respective floras. Let us further take into consideration the 

 meteorological conditions in both Alpine regions. Mr. James 

 Stirling, F.G S , F.L.S., in a paper — "The Physiography of the 

 Australian Alps " — read before the Australasian Association for 

 the Advancement of Science, held at Sydney in 1889, says : — • 

 " Snow falls at heights above 2,000 feet, but at the lower levels 

 seldom remains longer than a few days, thawing quickly as it falls 

 unless in the shaded hill sides, where the frost hardens the crust." 

 The height at which snow remains during the winter months 

 begins with 5,000 feet. From here upward the first snowfall 

 appears about the month of April, and melts in the month of No- 

 vember. The snow, therefore, remains in these elevations during 

 a period of seven months, thus leaving a vegetative period of five 

 months. In contrast to this are the meteorological conditions of 

 the European Alps in question. There snow melts, at the same 

 altitudes as in the Australian Alps, about end of May, in less 

 favourable situations not till the end of July. The snowfall 

 commences often in the middle of October, thus giving the 

 vegetation a winter rest of 7^^ to 9^ months, and a vegetative 

 period of only ajS^ to 4^ months. 



A similar difference will be observed in the respective tempera- 

 tures. The average mean summer temperature of Mount Hotham 

 is 55° F., in the European Alps it is 59" F., while the average 

 mean winter temperature for the Australian Alps is 41° F., and 

 for the Eastern European Alps 30° F. According to these 

 records there is in the Eastern European Alps a shorter time 

 available for the development of plants, though with a greater 

 range of temperature than in our Alps. 



The result of this short vegetative period is that in neither of 

 the Alps can annual species find the favourable meteorological 



