First it was The Black Cloud; then it was the Lifecloud; now it's the disease cloud. Thus, in a progression from science fiction, Hoyle seems intent on perpetuating the notion of the continuous creation of complex living forms of biological universality in interstellar space. Here, he and his colleague have extended the notion of interstellar life-seeding to viral- and bacterial-seeding. Influenza and the common cold, we are told, are not transmitted by sneezing or touch, but from space fallout. The details involve the incubation of microorganisms in the hearts of comets which eventually cross Earth's pathway. The organisms are supposedly unleashed in some kind of protective jacket, bounce around in the stratosphere and troposphere,and eventually cling to raindrops or particulate matter to fall on Earth. Plagues and pandemics, the authors posit, couldn't possibly be due to the emergence of virulent strains from Earthly reservoirs; they must originate from a patchy fallout from on high. Patchy indeed. By their own accounts--based in part on flu sickdays among British schoolchildren--the virus that affects School A avoids nearby School B, or hits this dormitory but not that. Other presumptions and assumptions are made on the basis of historical records or the absence thereof: ""The fact that there is no description of measles either in Hippocrates. . . or in the Indian medical writings of the sixth century B.C. may be interpreted as the absence of disease during this period."" Hoyle and his partner seem not to have taken into account that viruses and bacteria co-adapt with Earthlings. It is not credible, therefore, that ""microbes which had the potential of causing human disease began to arrive here well ahead of our emergence as a species""--in spite of facile theorizing that human genes are amalgams of this or that bit of viral or bacterial DNA. Much brilliance, less sense.