THESES. O. HERMAN. 



such as departed later (cf. also Andersen in „Aquila" X). This shows 

 a Migration in tribes, and also tribal distribution. 



27. According to Emin Pascha's observations at Lado Africa lat. 

 5" 2' N. long. 50" 0' E. fr. Ferro. — Hirundo rustica leaves on an 

 average on the 20th of March, therefore 35 days later, than she arrives 

 at Gibraltar (v. above) a direct proof that the Swallows hiber- 

 nating at Lado are destined for other northern regions. 



28. In the Forrester's house on the Hagi in the Tatra — 1 000 Metres 

 a. s. I. — Hirundo rustica arrives about the 5th of May, thus 28 days 

 later than the average for the whole country (Hungary), taken on 

 10,000 dates: 7. of April: Hegyfoky. 



On Hideghavas — 1320 Metres — the Swallow arrives on the 13th 

 of May, therefore 36 days later than the average, and from 61 to 69 days 

 later than the earliest date of arrival : the 5th of March 1898: DeGaal. 



29. That Birds living in the extreme North leave their winter-quar- 

 ters comparatively late, is proved by the following observations: 



Africa, Cape Blanco -- lat 20" 0' N., long 1" 0' E. fr. Ferro: Sterna 

 macroura, Strepsilas interpres, Calidris arenaria, Tringa canutus and 

 Tringa minuta were still noticed between 6th and 10th of May (DE 

 SCHACK etc.). 



30. The facts that migratory Birds leave us in the fall, whereas those 

 in the South leave with the beginning of the rainy season, is already 

 sufficient to prove the organic connexion between the Phenomena of 

 Migration and the changes of weather. Observations and their working 

 out must therefore be carried on in organic connexion. 



31. Just as in Meteorology there are no two years absolutely alike, 

 so it is in regard to Ornithophaenology. In both these branches of 

 Science therefore, year by year, observation and methodical treatment 

 is required as a „conditio sine qua non". 



32. Bird and Plant are phaenologicaly distinguished by the fact, 

 that the first frees himself from the influence of weather, whereas the 

 Plant is constantly subject to it. 



teo 22 lao 



