NOTICES ON THE PUBLICATION OF THE “ MONOGRAPHS 
71 
reproduce the long story of this delay, and of the excuses and 
apologies offered by Loew for it. Some of them were well 
founded: illness of himself and family (1866) ; the Austro-Prus- 
sian war, in which his three sons were engaged; his retirement 
from his position in Meseritz and his moving to Guben (1868). 
Nevertheless, the fact remains that Loew during these years did 
not relax his usual ardor in describing new species of Diptera. 
The “ Centuries of North American Diptera ” continued to appear: 
Century VI (1865), VII (1866), VIII, IX (1869), X (1870). The 
Prefaces of the new, large work, undertaken by Loew, “ Beschrei- 
bungen europaischer Dipteren,” are dated, that of Vol. I, October, 
1868; that of Vol. II, December, 1870. Besides these works, the 
list of Loew’s papers contains between 1865 and 1870 about fifty 
numbers, representing publications in the Berl. Eat. Zeit ., Wien. 
Eat. 3fonats., Zeitschr. gesammt. Naturw., Zeitschr. Entoni. Schles. 
Ver ., Jahrb. Gel. Ges. in Krakau , Bull. Soc. Ent. Ital ., and in 
several other periodicals. The truth is, that Loew was much 
averse to monographic work on a larger scale, requiring long 
preliminary studies and a mental concentration possible only in 
a state of repose. lie much preferred work of a kind that he 
could take up or put down at any time, I mean the work of pro¬ 
ducing a large number of short, disconnected articles, such as 
descriptions of new species, critical summaries of small groups 
of Diptera, local lists of species, etc. This manner of work may 
have been easier and more handy for him in his circumstances, and 
among the multitude of various occupations which his insatiable 
energy required. But, if such was the case, he should at least 
have been candid about it, and have openly avowed his preference ; 
and it would have been an easy matter to make arrangements to 
suit him. 
I had written down the above paragraph for some time, when, in looking 
over Loew’s correspondence, T came across the following passage which confirms 
exactly what I have been saying. Loew's letter is dated February 5, 1865, that is, 
before my visit to him during the summer of the same year : “ I believe that we 
shall, ultimately, agree on this point, that although this kind of publication [the 
Centuries] is inferior in quality to the publication in ‘ Monographs,’ it offers the 
advantage of a rapid publication of many new species. And the reason is, that 
every attempt at determination which proves the species to be new becomes at 
