358 Mr rhilip Sewell's Ohservations upon the 



V. The following after the 70th day : — 



Total. Max. observed on 



S. alho-ccenilea, ... 2 per cent. 70th day. 



VI. A few seeds germinated in each of the following 

 at very different dates, but the seedlings have failed to 

 develop : — 



S. Dominica. 

 S. Greggii. 

 S. nutans. 

 S. Linkiana. 



VII. The following had shown no signs of germination by 

 the 130th day : — 



S. confertiflora. 

 S. gesnera^flora, 

 S. graveolens. 



We may note, in conclusion of this part of our subject, 

 that out of the twenty-five species sown only six produce 

 more than 40 per cent, of seedlings, only half of the total 

 number produce 25 per cent., whilst more than a quarter 

 produce a smaller percentage, of which only one or two 

 individuals survive in most cases. In three species no 

 germination has been observed. 



The Cotyledons. 



Just as we have observed but little difference in the sizes 

 of the nutlets, so among these species of Salvia there was not 

 much variation in the size of the cotyledons at the time 

 when they first made their appearance above the soil. 



The seeds being exalbuminous, the size of the cotyledons, 

 as they emerge from the coats of the nutlet, has strict 

 dependence on the character of the nutlet ; they are longer 

 or broader, according as we have noticed the seed to be 

 longer or broader ; thus they entirely fill the seed, having 

 only towards their base a minute radicle and plumule, which 

 together lie sunk in a tiny depression. The coats of the 

 nutlet are ruptured at the base by the convergence of the 

 radicle ; they split as the cotyledons enlarge, and are thrown 

 off when these are below the soil. When the free cotyledons 

 make their appearance through the soil, pushed up by the 

 straightening of the somewhat stout hypocotyl, the apex of 



