SCIENCE. 



[N. S. Vol. V. No. 126. 



While we must thus congratulate the German 

 Zoological Society upon the eminently satis- 

 factory beginning of its enormous enterprise, 

 and the zoological world at large upon the 

 prospect of the assistance and stimulus which 

 such a work must necessarily afford, we cannot 

 forbear expressing the reservation that the pro- 

 motors of the task when expecting that ' Das 

 Tierreich ' may become the foundation and 

 starting point of all future systematic research 

 (' Grundlage und Ausgangspunkt aller kiinf- 

 tigen Systematik '). A work to become, in 

 our days, the foundation and starting point of 

 future systematic research must break new 

 ground, open up new views and utilize new 

 material to a much greater extent than it is 

 possible in a general work of the scope of ' Das 

 Tierreich, ' with its necessarily excessive conden- 

 sation and also necessarily uneven authority. 

 No matter how prominent the monographers 

 may be, it is conceivable that the work of many 

 may fail to receive the universal acceptance 

 which is essential to the fulfilment of the So- 

 ciety's fond hope. The time is not ripe yet for 

 a new starting point. We are still in the midst of 

 a period of development and upheaval. The 

 natural relationships of animals are, to a great 

 extent, obscure as yet, and the systematic ar- 

 rangement in the work is bound to be greatly 

 artificial in many groups at least. It is even to 

 be feared that the very conciseness of the form 

 and the consequent unavoidable preciseness of 

 the statements, coupled with the superficial 

 uniformity of the ari-angement, may tempt the 

 habitual generalizers, who are deficient in the 

 special knowledge which ' Das Tierreich ' is des- 

 tined to be an expression for, into a belief that 

 zoological science has reached a well-balanced 

 uniformity which might make it safe to use the 

 work as an undisputed authority in all branches 

 upon which to build daring and glittering gen- 

 eralizations. For the working specialist, it is 

 safe to say, no general work, however, well 

 executed, will even supersede the Systema 

 Naturae of Linnaeus as a starting point. 



Leonhaed Stejnegee. 



A Study in Insect Parasitism : A Consideration of 



. the Parasites of the White-marked Tussock Moth, 



with an account of their habits and interrelations, 



and with descriptions of new species. By L. O. 



Howard. U. S. Department of Agriculture, 



Division of Entomology, Technical Series 



(Bulletin) No. 5. [April] 1897. 



One of the first insects which met the writer's 

 eye on landing in New York in 1887 was the 

 larva of the white-marked tussock moth (Orgyia 

 Hemerocampa leucostigma). It is a beautiful 

 creature, but destructive to the shade trees. 

 It exhibits 'warning colors,' and is not eaten 

 by the sparrows ; so there is no telling how 

 abundant it might become but for parasites and 

 diseases. 



Dr. L. O. Howard undertook a few years ago 

 to study the life history and parasites of this in- 

 sect, especially as observed in the City of Wash- 

 ington. One might have supposed that at this 

 late date there was nothing new to be learned 

 about so common a creature, but Dr. Howard 

 knew better, and the present bulletin exhibits 

 part of the new facts ascertained. It is not 

 necessary to recount these facts, as the bulletin 

 itself can be obtained without difiS.culty, but I 

 should like to emphasize two or three points. 



In the first place, we see that most admirable 

 work may yet be done even in the very midst 

 of our great cities, and that even new species 

 may be obtained in tolerable abundance. Dr. 

 Howard, in the present bulletin, records thirty- 

 five parasites and hyperparasites of the Orgyia, 

 of which no less than nine are described as new, 

 all the new ones being from the District of Co- 

 lumbia. So even our business men, who have 

 but a spare half-hour or twenty minutes at 

 noon, can, if they are so inclined, gather a lot 

 of Orgyia cocoons and breed parasites, with a 

 fair chance of turning up actual novelties ! 

 Here, indeed, is an exciting and interesting 

 pastime for young clerks and such persons 

 whose city life is at present rather dull. 



Secondly, we observe that when the various 

 factors bearing upon the life of an insect are 

 considered together, the interest of the subject 

 is enormously increased. It is unfortunate that 

 at least nine-tenths of the current literature of 

 entomology relates either to dead specimens 

 removed from their natural environment, or 

 when referring to living insects takes an ex- 

 tremely narrow view of the subject. It results 

 from this that one of the most fascinating 



