3U0 



of as miicH as 16d° F. (9-15° C.)- This is Avliat he said iu writing,' 

 to Kew on Jaraiary 6th and 31st : — 



January 6th. — '' I have inmy garden a i^hmt of Ejicephalartos 

 nUdebrandtii noAV in male cone. There are six cones close 

 together in the crown, and last night when walking 

 home with two in my hand, I noticed a strange fact 

 worth noting and following up, both in this and other 

 species. The cones were in paper — I had them in a bag, the 

 sun had set, and there was notliing to disturb the tempera- 

 ture, but on taking them out to show some friends at home, I 

 found them very hot. I placed them in a cloth with a thermometer 

 that reached outside; the air was then 81-5°, and soon the cones 

 rose to 98°, being .16-5° above the air. I left them there all night, 

 and although they had been- at an open window and exposed to the 



night air, they still were 6° above the air, which was 80°, while the 

 cones showed 86°. They were then perfecting the pollen, which 

 fell from the scales when shaken. I must try this on the cones 

 when still on ilie plant, for tliose I observed witli had been sepa- 

 rated, but I doubt not this is a remarkable instaiice <\i heat 

 generated as in arums at tlie time of forming tbe judlen. I have 

 a male Cyras now coming; on, and shall tr^^ it in that also. 



January 31st, — " I have, since writin*^ on tlie 6th inst., verified 

 my observations on the temperature of the male cones of Enceph- 

 alartos HildehraadtiL The temperature is highest as the pollen 

 is being matured and wlien tbe first can be shaken out. I have 

 also made a practical experiment on the large male cone of our 

 Cycas sp. Unluckily it has been brought to me when ripening the 

 pollen, so that I have only an indication that the same phenomenon 

 will be found in it. The rise of temperature was distinct. I have 

 Ibeen very careful to aA'oid all chance of error, and this is rendered 

 impossible by the &mall mass of the cone of Ence-pliaJarto^, wbich 

 could not retain solar heat inside and show as if it had originated 

 heat. Besides, in the last stage of my experiment, there had 

 been no sun all day, and the cone was quite cold and rose to its 

 high temperature. I daresay all this is well known to you, but I 

 have fcAV works of reference here.'^ 



Encephalartos Hildebrandtii and E. villosus. — Shortly after 



H 



hram 



ultii by A, Braun and Bouclie, the validity of the vSjx^cies was 

 itioned by E. Regel,* and its identitv witb Lehmann's' 



questu 



E. villosuSj a native of I^atal, suggested. No reasons for this 

 reduction were then stated, bcj^ond that '^^ the fronds of more 

 luxuriant specimens seen at Berlin, Cologne and Brussels pass 

 into those of E. villosiis,^^ A. Braun replied to E. Rogers' criti- 

 cism the same year,t pointing out the differences in the vegeta- 

 tive structure and in the female cones. According to him the 

 stems of E. villosus are relatively stouter than those of E. Hilde- 

 brandtiiy the petioles are thrown off earlier, so that the trunk 

 appears armed by their persistent bases close up to the crown, the 

 leaves are le>s bard and punirent, the teeth of the ninnae (4-9 on 



* In Garcenflora (1876), p. 204. 



t A. Braun in Sitz. Ber. Gesellsch. Xaiurf. Freund, (1S7C), pp. 118-123. 



