FERTILISATION. 



83 



ascertainment of the time that elapsed from the pollination of the 

 flower to the fertilisation of the ovule, the remaining time necessary 

 to complete the matm-ation of the capsule seems to have been regarded 

 by him as a matter of subordinate interest, important as it is from 

 a cultural point of view ; this epoch is by no means easy to 

 determine precisely, for although the dehiscence of the capsule may 

 be selected as the epoch of maturity, experience has long since 

 shown that under the artificial conditions in which cultivated 

 plants are placed, the seeds are often iu a fit state to germinate 

 some time before the capsule dehisces. In our houses the 

 time required for maturing the capsules of the Cattleyas of 

 the labiata race ranges from eleven to thirteen months ; for 

 Lcelia purpurata it is about nine months; for Phalcenopsis Schilleriana 

 six months, Giipripedium Spicerianum eleven to twelve months, 0. 

 insigne ten months, Odontoglossum maculatum, Dendrohimn aureum, 

 Anguloa Glowesii, Ghysis hractescens and Bifrenaria Rarrisonice each 

 about twelve months, Masdevallias about four months, and Calanthes 

 of the Vestit.t; section from three to four months. These periods 

 are, however, only approximate; the time required for the ripening 

 of the capsules is considerably influenced by the state of the weather 

 and other external circumstances, especially by the amount of direct 

 sunlight ; in the warmer and drier climate of Paris the periods are 

 somewhat shorter. 



With the object of determining more accurately, if possible, the 

 processes that take place from the pollination of the flower to the 

 maturation of the capsules, a series of investigations were made in 

 our houses iu 1885-87. The subject selected for this end was the 

 well-known Gattleya labiata var. Ahssice, Lindl., because we could 

 command a large number of plants for the purpose ; and because 

 also the column and its parts are among the largest to be found 

 iu the Orchide.k, the probability of obtaining useful results would 

 thence be the greater. These results were formulated in a paper 

 read before the Linnean Society in February, 1888, and from it we 

 select the most salient points ; to enable the reader to obtain a 

 clear comprehension of these the following structural details are 

 necessary. 



The annoxeil figure (1) represents a front view of the colunni and 

 ovary of Cattleya labiata var. Moasia' a few days after the expansion 



