350 



the margin showing teeth like those of a comb. By iDfectingthe plant 

 at difiterent times either the leaves or the flowers may be iDfluenced, 

 and it appears that the parasite must attack the organ in its earliest 

 stages. Professor Peyritsch thinks that there are certain mites which 

 produce double flowers in certain plants, as the mites in which he was 

 particularly interested were always most abundant in certain. species 

 and less so in others. The experiments are recorded in the Trans- 

 actions of the Imperial Academy of Yienna^Yo\. XCVII, I. p. 597. 



"The plants of Valerianacea' experimented ujdou include Valeriana 

 (twelve sp.), ValerianeUa (three sp.), Fedia, Centi^ayithiis {ihreQ sp.), Pat- 

 rinea. Abnormal leaves were induced in ten species of Valeriana, all 

 of the VaJerianeUas, trwo of CentrantJms, Siud in Fed ia. Double flowers 

 were produced in Valeriana in six cases, three times in Centranthus, and 

 once each in Fedia and VaJerianella. Among the Crucifers Professor 

 Peyritsch worked on Biscutella, Brassica nigra, Capsella hursa-pastoris, 

 Cochlearia officinalis, Fnica, Lepidium, Malcolmia (two sp.), and Sisyni- 

 brium sopliia. Various were the results; in many of the cases (Coch- 

 learia, Fruca, Lepidium, Sisymbrium, Brassica, Capsella) bracts were 

 formed resembling the leaves, but of smaller size ; i)roliferous flowers 

 w^ere formed in Brassica and Biscutella ; petalody of stamens occurred 

 in Cochlearia and Eruca. In Linaria cymbalaria peloriate flowers and 

 other changes were found. 



" Professor Peyritsch says that the results are eifective or not accord- 

 ing as the plant is a good host-plant for the mite — a good host-plant 

 being quite crippled. 



"Among the Valerians, those plants with their leaves were more easily 

 affected than others with more substance. 



'•'The Phyioptiis infesting the buds of the Hazel, Corylus, and which 

 causes malformations in it, was transferred to plants of Brassica, 

 Sisymbrium, Capsella^ and Myagrum. Bracts were, in consequence, de- 

 veloped in Sisymbrium, Capsella, and Myagrum, in which, as in most Cru- 

 cifers, the bracts are generally wanting; and in the last-named double 

 flowers. 



''' Belli s per ennis gave the same results when infected by the mites from 

 Valeriana, Campanula, or Corylus, viz, the production of very hairy 

 leaves, but not toothed, the disc florets green, and the involucral bracts 

 elongated. 



" It was observed that after infection growth in length was slow, but 

 lateral bud develoi)ment was accelerated unless other abnormalities ap- 

 peared." — [XJdo Banimer, Berlin. — Gardeners'' Chronicle, March 16, 1889, 

 Vol. V, p. 333. 



EHEUMATIS3I AND THE STINGS OF BEES. 



"A very nice supply of bee literature is furnished from week to week 

 in the British Bee Journal. Amongst other wonderful discoveries of 

 the present day it appears to have been reserved for Dr. Tere to have 



