4 JOURNAL OF THE [January, 



insects, the Protococcus was apparently killed. But during the 

 month of August, about a week after the trees had been cleaned, 

 a rain-storm set in, which lasted nearly three days. The 

 growth on the trees that had been cleaned was apparently as 

 vigorous as on those that had not, giving the impression that 

 the polysolve had either not killed the Protococcus, or that a 

 new growth had rapidly been formed from the germs in the air. 



The following is a list of loo trees which are prominently 

 affected with Protococcus viridis in Central Park. 



Magnolia glauca, Linn. 



acuminata, Linn. 

 cordata, Michx. 

 macrophylla, Michx. 

 Umbrella, Lam. 

 conspicua, Salisb. 



On the Magnolias the growth is only near the 

 ground and not abundant. 

 Liriodendron tulipifera, Linn. — Luxuriant, and of a bright 



yellow green color. 

 Tilia Afnericana, Linn. 

 Puropcea, Linn. 

 heterophylla. Vent. 

 alba, Waldst and Kit. 

 Not abundant, and chiefly at the base. 

 Ptelea trifoliata, Linn. — Abundant and luxuriant. 

 Ilex Dahoon, Walter. 

 opaca. Ait. 



Not abundant, and near the base. 

 Euonymus atropmpureus, Jacq. 

 EtiropcBus, Linn. 



Abundant on both trunk and branches. 

 Rhamnus catharticus, Linn. — Little if any was observed upon 



this tree ; the bark does not seem to be a suitable habitat. 

 ^sculus Hippocastanum, Linn, 

 flava. Ait. 

 Californica, Nutt. 

 Neither abundant nor vigorous. 



