In iirdi'f ti> (k'ti'i'iniiu' wIk'iIht tliis siihstaiu'c was iiis()liil)le in prcstMic*.- <it 

 waliT, 6i\ s(,-etls were kept in mid hIckIioI for twenty-four lionrs, and diirini; that 

 time tliere was no change eitlier in tlie enlor of tiie seeds or in tlie (eii lontcni.-. 

 Tlie seeds were tai<i'n from the aicidinl and placed in water, and witliin tlirce 

 hours they hail turned hhick, and the iilue was deveh)ped in the cells. Dry ^ced.s 

 were placed in i>!acial acetic acid, and within twenty-lour iionrs they were turned 

 a liulil yellow ((dor and sections showed the ceil contents to lie colorless. 'J"ln>i 

 seeds were taken li'oni the aci<l an(i kej)t in water tor twelve hours, and durinji 

 that time no furtlier change took place. Dry seeds were phiced in strong ammo- 

 nia, and within twelve hours tlu-y had turned lilack on the surface and the cell 

 contents wen- turned hrown. .\fter this treatment with ammonia, the seeds were 

 kept in water for several hours, hut no lurther change was jn'rceptihle. The di-v 

 seeds weri' kept in pure chloroform for tiiree days, and during tiiat lime llu-y re- 

 tained their golden yellow color and the cell contents also remained colorless. 

 Tlien they were taken from the chloroform and phu'ed in water, and within three 

 hours tlu'y had turned l)lack, and tiu- Mue was (leveloi)ed in tlu' cells. 



After the color had been developed l)y water, sections were treated witli nitric 

 acid, and the hlue I'olor disa))])eared immediately, leaving the cell contents a yel- 

 lowish lirown coloi-. The blue was turned green immediately upon iieing treated 

 with sodic hydrate, hut was changed to i)lue again within twelve hours after being 

 placed in glycerine. On account of the small amount of material it was impos- 

 sible to carry these experiments to a conclusion. 



A blue substance is developed l)y water in the seeds of P. Patai/onica also, imt 

 no chemical experiments were nuide uixm these seeds. 



P. Vinjinira and P. PafcKjonica were the only species examined in the genus 

 Plantaijo which showed this peculiar development of color. 



The test for this su!)stancc in the indigo plant itself was made upon an her- 

 bai'ium s|)ecimen and failed to produce it. The indigo plant must lie taken at 

 certain stages of its development in order to prodiu-e Tndican, and such may be 

 the case in Plantufio Virr/i)iic>i. 



Root Systkm of Pogoni.v. By M. B. TtioMAS. 



The genus Pogonia is a remarkably interesting group of orchids represented' 

 by live species in northeast North .\merica out of a total of forty-three in the 

 whole genus. 



The species have a very wide distribution, being found throughout North 

 America,- .Vfrica, eastern .\sia, and. to a very limited extent, lliroughonl Europe, 



